ES2890798T3 - Protection devices against overvoltages, overcurrents and electric arc - Google Patents

Abstract

A circuit protection device comprising: an electric arc, overvoltage, overcurrent and overload protection system (100) that is connected between a plurality of phase lines (L1, L2, L3) and a neutral line (N) that are between an incoming power supply line and an electrical load panel (62) in electrical equipment, or are connected between the plurality of phase lines (L1, L2, L3); where: a) the protection system against electric arc, overvoltage, overcurrent and overload comprises: a lever device (102) that is coupled to the plurality of phase lines (L1, L2, L3) and to the neutral line (N) and is configured to prevent an overvoltage condition by generating through at least one thyristor a low resistance current path from the plurality of phase lines to the neutral line; a plurality of surge protection devices (104) that are connected to the plurality of phase lines and to the neutral line and that are configured to protect the equipment during an overvoltage condition by conducting a limited amount of current corresponding to the overvoltage condition overvoltage; and a toggle drive circuit (106) that is configured to cause the toggle device to turn on and provide the low resistance current path from one of the plurality of phase lines to the neutral line; or b) the arc flash, overvoltage, overcurrent and overload protection system comprises: a toggle device that is coupled to and between the plurality of phase lines (L1, L2, L3) and is configured to prevent an overvoltage condition by selectively generating through at least one thyristor a low resistance current path between the plurality of phase lines; a plurality of surge protection devices that are connected to and between the plurality of phase lines and that are configured to protect the equipment during an overvoltage condition by conducting a limited amount of current corresponding to the overvoltage condition; and a toggle drive circuit that is configured to cause the toggle device to turn on and provide the low resistance current path between the plurality of phase lines; and characterized in that the toggle drive circuit comprises: a plurality of thyristor drive circuits (168) that are configured to generate thyristor drive signals that are received by the toggle device; a power source and a voltage hold circuit (166) that is configured to receive electrical power for the lever actuation circuit and to provide power to the lever actuation circuit for a period of time after power is lost electrical for lever actuation circuit; and an interface circuit (164) that is configured to receive inputs corresponding to voltages from the plurality of phase lines, current flow through the plurality of phase lines, an arc signal, and/or temperatures from the respective overload protection devices.

Description

DESCRIPTION

Protection devices against overvoltages, overcurrents and electric arc

Related Request(s)

This application claims the benefit and priority of US Provisional Patent Application No. 62/135,284, filed March 19, 2015.

field of invention

The present invention relates to circuit protection devices and, more particularly, to overvoltage, overcurrent, and arc flash protection devices and methods.

Background

Excessive voltage or current is often applied through service lines that supply power to residences and commercial and institutional facilities. These excess voltage or current spikes (transient overvoltages and overcurrents) can be the result of lightning strikes, for example. The above events can be of particular concern in telecommunications distribution centers, hospitals and other facilities where equipment damage caused by power surges and/or surges and the resulting downtime can be very costly.

Typically, sensitive electronic equipment can be protected against transient overvoltages and overcurrents through the use of surge protection devices (SPDs). For example, brief reference is made to Figure 1, which is a system including conventional surge and overload protection. A surge protection device 10 may be installed at a power input of the equipment to be protected 50, which is normally protected against surge currents. The typical failure mode of an SPD is a short circuit. The overcurrent protection normally employed is a combination of an internal thermal disconnector to protect the device from overheating due to increased leakage currents and an external fuse to protect the device from higher fault currents. Different SPD technologies can avoid the use of the internal thermal disconnector because, in case of failure, they change their mode of operation to a low ohmic resistance. In this way, the device can withstand large short-circuit currents. In this sense, there may be no operational need for an internal thermal disconnector. In addition to the above, some embodiments showing even higher short-circuit withstand capabilities may also be protected only by the installation's main circuit breaker without the need for a dedicated bypass fuse.

Brief reference is now made to Figure 2, which is a block diagram of a system including conventional surge protection. As illustrated, a three-phase line can be connected to and supply electrical power to one or more transformers. 66, which in turn may supply three-phase electrical power to a main circuit breaker 68. The three-phase electrical power may be provided to one or more distribution panels 62. As illustrated, the three three-phase electrical power voltage lines may be designated as L1, L2, and L3, and a neutral line may be designated N. In some embodiments, the neutral line N may be conductively coupled to ground.

Some embodiments include surge protection devices (SPDs) 104. As illustrated, each of the SPDs 104 may be connected between the respective ones of L1, L2, and L3, and neutral (N). The SPD 104 can protect other equipment in the installation such as the distribution panel among others. Additionally, SPDs can be used to protect all equipment in case of prolonged surges. However, such a condition can force the SPD to carry a limited current for an extended period of time, which can result in the SPD overheating and possibly failing (depending on the energy-withstanding capabilities that the SPD can absorb and the level and duration of the overvoltage condition). A typical operating voltage of an SPD 104 in the present example may be approximately 400V (for 690V L-L systems). In this sense, the SPDs 104 will each function as an insulator and therefore will not conduct current during normal operating conditions. In some embodiments, the operating voltage of the SPDs 104 is sufficiently higher than the normal line-to-neutral voltage to ensure that the SPD 104 will continue to function as an isolator even in cases where the system voltage increases due to overvoltage conditions. that may arise as a result of a power loss or other power system problems.

In the event of an overcurrent on, say, L1, the power system's load device protection may need to provide a current path to ground for the excess current from the overvoltage. The surge can generate a transient between L1 and N. Since the surge significantly exceeds the operating voltage of SPD 104, SPD 104 will become conductive, allowing excess current to flow from L1 through SPD 104 along neutral N. Once the overcurrent has been conducted to N, the overvoltage condition ends and the SPD 104 can become non-conductive again. However, in some cases, one or more SPDs 104 may begin to allow leakage current to be conducted even at voltages that are lower than the operating voltage of the SPDs 104.

Additionally, within an electrical appliance cabinet there may be devices that can protect the equipment within the cabinet and nearby personnel from electrical arcs that could be generated within the cabinet. An electrical arc that occurs inside a cabinet can create serious damage and is considered a very serious safety hazard to personnel. As such, the detection of the electric arc and the interruption of the corresponding current must be as fast as possible to minimize damage and/or risks. However, especially in high power systems, during an arc flash, the fault current could be limited to a level lower than the current threshold required for the main breaker to trip fast enough. Faster response times may be required to avoid damage and/or risk. A solution used by many manufacturers includes an electronic system to force external activation of the circuit breaker. During an arc flash, there can be a significant increase in pressure within the cabinet and a significant increase in lighting. An electronic circuit may use optical and/or pressure sensors to detect the presence of an electrical arc and activate the circuit breaker. Other newer techniques use readings of the power system voltage and current and trip the breaker when specific patterns of these readings are found.

However, the time it can take for a circuit breaker to disconnect the system from the power source (after being externally activated by electronic circuitry) can be on the order of 100 milliseconds or more. During this time, a short-circuit current that can range from about 10 kAmps to about 100 kAmps can cause damage to internal parts of the equipment as well as expose nearby personnel to significant danger.

Document KR100981787 describes an integrated device that includes a voltage control regulator for the elimination of non-polar overvoltages. EP1058366 describes a surge suppression network for single and multiphase AC systems. WO2008/153578 describes a MEMS-enabled apparatus for detecting arc faults and eliminating arc flash conditions, comprising an arc flash detection component and a current limiting component. US4912589 describes an activated surge suppression network comprising a low voltage clamping device, a lever device and an activating device. Document CN2321155 describes a lightning rod for electronic equipment, in particular a lightning rod that is arranged on signal input lines.

Compendium

The present invention, as defined in claim 1, is directed to a circuit protection device that includes an electric arc, overcurrent, overvoltage, and overload protection system that is connected between a plurality of phase lines and a neutral line. located between an incoming power supply line and an electrical load panel on electrical equipment.

In some embodiments, the arc flash, overcurrent, overvoltage, and overload protection system includes a toggle device that is coupled to the plurality of phase lines and the neutral line and is configured to prevent an overvoltage condition by generating a path of low resistance current from the plurality of phase lines to the neutral line, a plurality of surge protection devices that are connected to the plurality of phase lines and to the neutral line and that are configured to protect the equipment during a surge condition overvoltage by conducting a limited amount of current corresponding to the overvoltage condition, and a toggle activation circuit that is configured to cause the toggle device to turn on and provide the low-resistance current path from one of the plurality of phase lines to the neutral line.

Some embodiments provide that the toggle device includes a plurality of surge protection modules that are coupled between respective ones of the plurality of phase lines and the neutral line. In some embodiments, one of the plurality of surge protection modules each includes a bidirectional thyristor and an inductor that is connected in series with the bidirectional thyristor. Some embodiments envision that one of the plurality of surge protection modules each includes two thyristors that are connected antiparallel to each other and an inductor that is connected in series with the two thyristors. In some embodiments, the one of the plurality of surge modules further comprise a snubber circuit that is connected in parallel with the two thyristors. Some embodiments provide that the snubber circuit includes a resistor and a capacitor that are connected in series with each other.

In some embodiments, the arc flash, overcurrent, overvoltage, and overload protection system further includes an arc flash detection system that is configured to detect an arc flash within the equipment and generate and send an arc flash signal to the activation circuit. lever.

Some embodiments envision that the toggle drive circuit includes a plurality of thyristor drive circuits that are configured to generate thyristor drive signals that are received by the toggle device. In some embodiments, the lever activation circuit further includes a power supply and voltage hold circuit that is configured to receive electrical power for the activation circuit and to provide power to the activation circuit for a period of time after electrical power to the drive circuit is lost, corresponding to an interface circuit that is configured to receive inputs corresponding to voltages from the plurality of phase lines, current flow through the plurality of phase lines, an electric arc signal and/or respective temperatures or overload protection devices, and a microcontroller that is configured to receive data from the interface circuit, to process the received data and to generate and send activation signals one or more of the plurality of thyristor trigger circuits, an alarm signal to a remote warning device, and/or a trigger signal to a main circuit breaker. Some embodiments envision that the power supply and voltage hold circuit includes a plurality of DC-DC converters operable to provide voltages to one of the plurality of thyristor drive circuits and a hold circuit that is configured to hold a voltage that is provided to the plurality of DC-DC converters.

Some embodiments envision that the toggle device includes a plurality of pairs of antiparallel connected thyristors that are coupled between respective ones of the plurality of phase lines and the neutral line, a plurality of inductors that are connected in series with respective ones of the a plurality of pairs of antiparallel thyristors, and a plurality of overload protection devices that are connected between the respective ones of the plurality of phase lines and the neutral line.

In some embodiments, the arc flash, overcurrent, overvoltage, and overload protection system includes a toggle device that is coupled to and between the plurality of phase lines and is configured to prevent an overvoltage condition by selectively generating a low current path. resistance between the plurality of phase lines, a plurality of surge protection devices that are connected to and between the plurality of phase lines and that are configured to protect equipment during an overvoltage condition by conducting a limited amount of current corresponding to the overvoltage condition, and a toggle drive circuit that is configured to cause the toggle device to turn on and provide the low resistance current path from one of the plurality of phase lines to the neutral line.

Some embodiments provide that the arc flash, overcurrent, overvoltage, and overload protection system includes a toggle device that is coupled to the plurality of phase lines and the neutral line and is configured to prevent an overvoltage condition by generating a current path. low resistance from the plurality of phase lines to the neutral line, a plurality of surge protection devices that are connected to the plurality of phase lines and to the neutral line and are configured to protect equipment during an overvoltage condition by conducting a limited amount of current that corresponds to the overvoltage condition, and an arc drive circuit that is configured to cause the toggle device to turn on and provide the low-resistance current path from one of the plurality of phase lines to the neutral line. In some embodiments, the toggle device includes a plurality of self-actuating toggle modules that are connected to the neutral line and respective ones of the plurality of phase lines.

In some embodiments, the plurality of self-actuating toggle modules each include two thyristors that are connected antiparallel to each other, an inductor that is connected in series with the two thyristors, and a toggle drive circuit that is configured to receive a trigger. current signal from a current sensor on the corresponding one of the plurality of phase lines and causing at least one of the two thyristors to provide a low resistance current path between the corresponding one of the plurality of phase lines and the neutral line in response to the current signal exceeding a current threshold.

In some embodiments, the lever drive circuit is configured to generate a drive signal in the absence of any arc drive circuit signal. Some embodiments provide that the lever drive circuitry is configured to provide automatic actuation of the corresponding module of the plurality of levers during an equipment start-up period. In some embodiments, the arc flash drive circuitry is configured to drive the plurality of toggle modules in response to detection of an arc flash after the equipment start-up period.

Some embodiments provide that the one of the plurality of lever modules further include a snubber circuit that is connected in parallel with the two thyristors and that the snubber circuit includes a resistor and a capacitor that are connected in series with each other.

In some embodiments, the arc flash, overcurrent, overvoltage, and overload protection system further includes an arc flash detection system that is configured to detect an arc flash within the equipment and to generate and send an arc flash signal to the control circuit. electric arc drive.

Some embodiments provide that the arc flash, overcurrent, overvoltage, and overload protection system further includes a threshold selector that is connected to the arc flash drive circuit and is configured to provide a threshold current selection signal corresponding to a value current threshold. In some embodiments, the threshold selector includes a user input device that receives a user input and provides the threshold current selection signal to the arc drive circuit. Some embodiments provide that the threshold current selection signal includes a discrete binary value, and wherein a lower value of the discrete binary value corresponds to a default threshold current.

Some embodiments of the present invention are directed to an arc flash, overcurrent, overvoltage, and overload protection system that includes a toggle device that is coupled to and between a plurality of phase lines and is configured to prevent an overvoltage condition by selectively generating a low-resistance current path between the plurality of phase lines and a plurality of surge protection devices that are connected to the respective ones of the plurality of phase lines and the lever device and that are configured to protect the equipment during an overvoltage condition by conducting a limited amount of current that corresponds to the overvoltage condition.

In some embodiments, each of the plurality of surge protection devices includes a first terminal that is connected to a corresponding one of the plurality of phase lines and a second terminal that is connected to the lever device. Some embodiments provide that the lever device includes a plurality of phase terminals that are connected to the plurality of overload protection devices and a plurality of thyristors that are connected between different pairs of phase terminals.

Some embodiments envision that the toggle device further includes toggle drive circuitry operable to generate thyristor drive signals to the plurality of thyristors in response to detection of a fault condition on the phase lines. In some embodiments, the lever drive circuit includes a rectifier circuit that generates a direct current (DC) signal corresponding to the voltages between the plurality of phase lines, a comparator that compares the DC signal from the rectifier circuit with a reference signal, and a plurality of isolation drivers that receive an output from the comparator and, in response to the comparator output indicating that the DC signal exceeds the reference signal, generate a drive signal that turns on the plurality of thyristors.

In some embodiments, the overload protection devices comprise metal oxide varistors.

Some embodiments of the present invention are directed to a surge protection system that includes a plurality of lever modules that are coupled to a plurality of phase lines and that are configured to prevent an overvoltage condition by selectively generating a surge current path. low resistance between the plurality of phase lines and a neutral line and a plurality of surge protection devices that are connected in series with respective ones of the plurality of lever modules to provide a plurality of series circuits each including, one of the plurality of lever modules and one of the plurality of overload protection devices, wherein each of the series circuits is connected between a corresponding one of the plurality of phase lines and the neutral line.

In some embodiments, one of the plurality of surge protection devices each includes a first terminal that is connected to a corresponding one of the plurality of phase lines and a second terminal that is connected to a corresponding one of the plurality of lever modules. . In some embodiments, one of the plurality of toggle modules each includes a plurality of antiparallel thyristors that are connected between a corresponding one of the plurality of surge protection devices and the neutral line and a toggle drive circuit operable to generating thyristor drive signals for the plurality of thyristors in response to detecting a fault condition on the phase lines.

In some embodiments, the lever actuation circuit includes a rectifier circuit that generates a direct current (DC) signal corresponding to a voltage on the corresponding one of the plurality of phase lines, a comparator that compares the DC signal of the circuit rectifier with a reference signal, a controller that receives the comparator output and, in response to the comparator output indicating that the DC signal exceeds the reference signal, generates a thyristor drive signal, and an opto-isolator that generates a thyristor drive signal in response to receiving the thyristor drive signal from the controller, wherein the thyristor drive signal turns on the pair of antiparallel thyristors to provide a low-resistance current path between the corresponding of overload protectors and the neutral line.

According to embodiments of the invention, a lever module includes first and second electrical terminals, a module housing, and first and second lever units. The first lever unit is disposed in the module housing and includes a first thyristor electrically connected between the first and second electrical terminals. The second lever unit is disposed in the module housing and includes a second thyristor electrically connected between the first and second electrical terminals in electrical parallel with the first lever unit.

In some embodiments, the first thyristor is connected antiparallel to the second thyristor.

The lever module may include a damper circuit disposed in the module housing and electrically connected between the first and second electrical terminals in electrical parallel with each of the first and second lever units.

The lever module may include a coil assembly electrically connected in series between the first terminal and each of the first and second lever units. In some embodiments, the lever module includes a damper circuit disposed in the module housing and electrically connected between the first and second electrical terminals in electrical parallel with each of the first and second lever units.

In some embodiments, the coil assembly includes: an electrically conductive coil element, the coil element including a spirally extending coil strip defining a spiral coil channel; and an electrically insulating casing including a partition wall portion that fills the channel of the coil.

In some embodiments, the module housing includes a cover that defines a closed cavity, the first and second lever units are contained in the closed cavity, and the lever module further includes a filler material that fills a volume in the closed cavity. not occupied by the first and second lever units. In some embodiments, the filler material is an epoxy.

The lever module may include a metal oxide varistor device disposed in the module housing and electrically connected between the first and second electrical terminals in parallel with each of the first and second lever units.

The lever module may include a drive circuit disposed in the module housing and electrically connected to the first and second lever units. In some embodiments, the lever module includes an electrical connection to an external current sensor.

According to some embodiments, the first thyristor includes a first contact surface that is one of an anode and a cathode, and a second contact surface that is the other of an anode and a cathode, and the first lever unit includes a first electrode electrically conductive that is in contact with the first contact surface, and a second electrically conductive electrode that is in contact with the second contact surface. In some embodiments, the first electrode is a unitary metal unit shell member including an end wall and a side wall, the end wall and side wall define a unit shell cavity, the thyristor is disposed in the cavity. of drive casing. The lever module may include a bias device that urges at least one of the first and second electrode members against the first or second contact surface.

According to some embodiments, the first lever unit includes: a unit housing defining a closed chamber, the first thyristor being disposed in the closed chamber; a cable port defined in a wall of the drive casing between the closed chamber and the exterior of the drive casing; a cable port mounted grommet; and an electrical cable that extends through the bushing from the outside of the unit casing and is electrically connected to the first thyristor.

The electrical lead wire may terminate at a control terminal of the first thyristor. The toggle module may include a second electrical lead wire extending through the grommet from outside the unit housing and electrically connected to a reference terminal of the first thyristor.

In some embodiments, the bushing is attached to the electrical wire. In some embodiments, the grommet includes a resin that is bonded to the electrical wire. In some embodiments, the resin is an epoxy resin.

According to some embodiments, the grommet includes: a tubular outer fitting secured in the cable port; and a sealing plug mounted on the outer fitting and surrounding the electric cable; wherein the sealing plug fills the radial space between the electrical cable and the outer fitting. In some embodiments, the sealing plug is attached to the electrical lead wire. In some embodiments, the outer fitting is formed of a polymeric material bonded to the housing of the unit.

According to some embodiments, the grommet mechanically secures the electrical lead cable to the unit housing and hermetically seals the cable port.

According to embodiments of the invention, a lever unit includes a unit housing defining a closed chamber, a thyristor disposed in the closed chamber, a cable port defined in a wall of the unit housing between the closed chamber and a outside of the drive casing, a grommet mounted in the cable port, and an electrical cable extending through the grommet from the outside of the drive casing and electrically connected to the thyristor.

In some embodiments, the thyristor includes a first contact surface that is one of an anode and a cathode, and a second contact surface that is the other of an anode and a cathode, and the lever unit includes an electrically conductive first electrode. that is in contact with the first contact surface, and a second electrically conductive electrode that is in contact with the second contact surface.

According to some embodiments, the first electrode is a unitary metal shell member that includes an end wall and a side wall, the shell member forms part of the unit shell and defines a shell cavity, and the thyristor is disposed. in the casing cavity.

The lever unit may include a pusher device that pushes at least one of the first and second electrode members against the first or second contact surface.

In some embodiments, the electrical lead wire terminates at a control terminal of the thyristor. The lever unit may include a second electrical wire which extends through the bulkhead from the outside of the unit housing and electrically connected to a reference terminal of the thyristor.

According to some embodiments, the bushing is attached to the electrical wire. In some embodiments, the grommet includes a resin that is bonded to the electrical wire. In some embodiments, the resin is an epoxy resin.

According to some embodiments, the grommet includes a tubular outer fitting secured in the cable port and a sealing plug mounted on the outer fitting and surrounding the electrical lead wire, wherein the sealing plug fills the radial space between the lead wire electrical and exterior accessory. In some embodiments, the sealing plug is attached to the electrical lead wire. In some embodiments, the outer fitting is formed of a polymeric material bonded to the housing of the unit.

According to some embodiments, the grommet mechanically secures the electrical lead cable to the unit housing and hermetically seals the cable port.

In some embodiments, the thyristor is a bidirectional thyristor.

According to further aspects of the present disclosure, a method of forming a lever unit includes: providing a unit housing that defines a closed chamber and includes a cable port defined in a wall of the unit housing between the closed chamber and an exterior of the unit casing; mount a thyristor in the closed chamber; routing an electrical lead wire through the wire port; seal the electrical cable in the cable port with a grommet; and electrically connecting the electrical cable to the thyristor.

In some embodiments, sealing the electrical conductor cable at the cable port with a grommet includes: forming a grommet, including inserting an electrical conductor cable into a tubular outer fitting, introducing a liquid sealing material into the outer fitting around the cable electrical conductor and curing or hardening the liquid sealing material around the electrical conductor cable to seal the electrical conductor cable in the outer fitting; and mount the electrical cable and the cable gland to the cable port. In some embodiments, the liquid sealing material is a resin.

According to embodiments of the invention, a lever device includes a device housing and a lever module and a current sensor disposed in the device housing. The lever module includes: a module housing; a thyristor arranged in the module casing; an automatic drive circuit arranged in the module casing; and a snubber circuit arranged in the module casing.

According to embodiments of the invention, a lever system includes a lever module and an external actuator and alarm interface circuit. The lever module includes: a module housing; a thyristor arranged in the module casing; a coil arranged in the module casing; a drive circuit arranged in the module casing; and a snubber circuit arranged in the module casing. The external actuator and alarm interface circuit is electrically connected to the toggle module.

It is noted that aspects of the invention described with respect to one embodiment may be incorporated in a different embodiment even though they are not specifically described with respect thereto. That is, all embodiments and/or features of any embodiment may be combined in any manner and/or combination. These and other objects and/or aspects of the present invention are explained in detail in the specification that follows.

Brief description of the drawings

The accompanying figures are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate some embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

Figure 1 is a block diagram of a system including conventional overload protection.

Figure 2 is a block diagram of a system including conventional overload protection.

Figure 3 is a block diagram illustrating an electrical arc and surge protection system according to some embodiments of the present invention.

Figure 4 is a block diagram illustrating an electrical arc and surge protection system according to some embodiments of the present invention.

Figure 5 is a schematic diagram showing a circuit including an electric arc and an overload protection system in a switchgear cabinet according to some embodiments of the present invention. Figure 6 is a schematic block diagram illustrating a drive circuit as briefly described above with respect to Figure 4, according to some embodiments of the present invention.

Figure 7 is a schematic block diagram illustrating a power supply and voltage hold circuit as described with reference to Figure 6.

Figure 8 is a block diagram illustrating an isolated DC-DC converter as discussed with reference to Figure 7.

Figure 9 is a schematic block diagram illustrating a thyristor drive circuit as discussed with reference to Figure 6.

Figure 10 is a schematic diagram depicting a circuit including an electrical arc and overload protection system according to some embodiments of the present invention.

Figure 11 is a schematic diagram showing a circuit including an electrical arc and overload protection system according to some embodiments of the present invention.

Figure 12 is a schematic diagram showing a circuit including an electrical arc and overload protection system according to some embodiments of the present invention.

Figure 13 is a top perspective view of a lever system and drive module according to some embodiments of the present invention.

Figure 14 is a cross-sectional view of the lever system of Figure 13 taken along line 14-14 of Figure 13.

Figure 15 is a top perspective view of a lever module that forms part of the lever system of Figure 13.

Figure 16 is an exploded, fragmentary top perspective view of the lever module of Figure 15. Figure 17 is an exploded top perspective view of a coil assembly forming part of the lever module of Figure 15.

Figure 18 is a cross-sectional bottom perspective view of a housing forming part of the coil assembly of Figure 17.

Figure 19 is an exploded bottom perspective view of a lever unit forming part of the lever module of Figure 15.

Figure 20 is a cross-sectional top perspective view of the lever unit of Figure 19. Figure 21 is an enlarged, fragmentary, cross-sectional view of the lever unit of Figure 19. Figure 22 is a rear perspective view of the connector module in Figure 13.

Figure 23 is a fragmentary perspective view of a lever module according to other embodiments of the invention.

Figure 24 is a schematic diagram illustrating an arc flash and surge protection system used in equipment protection according to some embodiments of the present invention.

Figure 25 is a schematic block diagram illustrating a lever module as briefly described above with respect to Figure 24, according to some embodiments of the present invention.

Figure 26 is a schematic block diagram illustrating a lever module drive circuit as briefly described above with respect to Figure 25, according to some embodiments of the present invention.

Figure 27 is a graph illustrating voltage and current values during an overvoltage condition according to some embodiments of the present invention.

Figure 28 is a schematic block diagram illustrating a lever module arc drive circuit as briefly described above with respect to Figure 24, according to some embodiments of the present invention.

Figure 29 is a schematic block diagram illustrating an overload protection system used in equipment protection according to some embodiments of the present invention.

Figure 30 is a schematic block diagram illustrating a lever device as briefly described above with respect to Figure 29, according to some embodiments of the present invention.

Figure 31 is a schematic block diagram illustrating an overload protection system used in equipment protection according to some embodiments of the present invention.

Figure 32 is a schematic block diagram illustrating a lever module as briefly described above with respect to Figure 31, according to some embodiments of the present invention.

Figure 33 is a top perspective view of a lever system according to some embodiments of the present invention.

Figure 34 is a top perspective view of a lever module that forms part of the lever system of Figure 33.

Figure 35 is a fragmentary, exploded top perspective view of the lever module of Figure 33.

Detailed description of the embodiments of the invention

The present invention will now be described in more detail below with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. In the drawings, the relative sizes of regions or features may be exaggerated for clarity. However, this invention can be embodied in many different ways and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this description will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It will be understood that when an element is referred to as "coupled" or "connected" to another element, it may be directly coupled or connected to the other element or intermediate elements may also be present. In contrast, when an element is referred to as "directly coupled" or "directly connected" to another element, no intermediate elements are present. Like numbers refer to like elements everywhere.

In addition, spatially relative terms, such as "under", "below", "inferior", "above", "above", and the like, may be used herein for ease of description to describe the relationship of one element or feature to another. Element(s) or feature(s) as illustrated in the figures. It will be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, elements described as being "under" or "under" other elements or features would be oriented "above" the other elements or features. Thus, the exemplary term "low" can encompass both an up and down orientation. The device may be oriented in another way (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

Known functions or constructions may not be described in detail for the sake of brevity and/or clarity.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated enumerated elements.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended as a limitation of the invention. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprise" and/or "comprising", when used in this specification, specify the presence of declared features, integers, steps, operations, elements and/or components, but do not exclude the presence or addition of one or more features, integers, steps, operations, elements, components and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as is commonly understood by one skilled in the art to which this invention pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, are to be construed as having a meaning that is consistent with their meaning in the context of the relevant art and are not to be construed in an idealized or overly narrow sense. formal unless expressly so defined herein.

According to the embodiments described herein, an arc flash and surge protection system can protect electrical distribution and control equipment from electrical discharges that may be generated within an enclosure, such as an electrical switchgear cabinet. In the case of an arch in the absence of the protections provided in this specification, an arcing short circuit can cause the circuit breaker to trip and open the circuit in approximately 100 milliseconds. In the event of a lower short-circuit current due to, for example, circuit impedance, an arc-flash detection system can cause the circuit breaker to trip. However, during this period, the short-circuit current, which may be between approximately 10kA and approximately 100kA, will damage the internal equipment inside the switchgear cabinet and may present a serious safety hazard to nearby personnel. of the switchgear cabinet.

As described herein, the above effects can be eliminated by using a toggle device that has a very fast response time ( eg less than about 5 milliseconds) and can conduct the fault current to eliminate the arc until the circuit breaker trips and disconnects the switchgear cabinet from the power source.

The toggle device may include two thyristors (one for each AC current direction) that when actuated can create a short that will conduct current and eliminate arcing. However, as stated in this specification, thyristors can be protected against damage from false triggers and/or overvoltages. Dummy drives can be protected against using the circuit components described herein and surge protection can be provided by surge protection devices that can be connected in parallel with the surge protection device. The use of the overload protection device can protect the thyristors of the toggle device from false actuations and other equipment in the installation.

In some embodiments, the toggle device may protect the surge protection device in the event that the surge protection device has failed. For example, the typical failure mode of such devices may be a short circuit that is interrupted by an internal thermal disconnect and/or an external fuse/circuit breaker. In this way, the toggle device can additionally protect the overload protection device in the event of a fault and thus avoid the need for a thermal disconnector and/or a fuse/circuit breaker in series.

Some embodiments envision that the lever device can be implemented in a number of different ways. A first example provides a one-time operation where the toggle device is used only once and a replacement toggle device is provided to replace the used toggle device. A second example includes a lever device that can be used multiple times. In this example, the toggle device can withstand the short-circuit current until the circuit breaker trips. As such, the toggle device can be restored after the fault event and allow for a possible reclosing of the main breaker which will allow the installation to resume normal operation (provided the problem that caused the toggle system to be actuated has been resolved).

To actuate the lever device, a separate electronic circuit can be used. This circuit can receive the drive signal from the arc flash detection circuit as input and can drive the toggle device and/or the main circuit breaker. In some embodiments, this circuit may also receive voltage and current readings from power lines and current readings from surge protection devices as inputs. In this way, the electronics can indicate the presence of a short anywhere downstream of the toggle device, if there is a prolonged overvoltage condition, and if the surge protection devices have failed. In any of the above conditions (or any other condition that is required and can be detected through the use of these sensors or additional sensors), the electronics can actuate the toggle device and the main circuit breaker.

Furthermore, the electronic circuit can also provide an alarm signal to indicate the presence and/or type of problem that caused the actuation of the lever device. Some embodiments envision that the toggle device may be actuated in response to one or more of the following conditions and/or events:

- Electric arc inside the cabinet;

- Failure of the overload protection device;

- Prolonged overvoltage or overcurrent conditions;

- Short circuit downstream of the lever device;

- Any other pattern of electrical disturbance in the system that can be detected using the existing sensors or installing additional sensors for that reason; Y

- Remote manual actuator.

Reference is now made to Figure 3, which is a block diagram illustrating an arc flash, overvoltage, overcurrent, and overload protection system according to some embodiments of the present invention. Some embodiments of the present invention may be applicable to the protection of equipment corresponding to systems distribution boards used in industrial installations including secondary distribution panels and/or a service entrance section of electrical generation installations, including, for example, wind turbines. However, such embodiments are not limiting. For example, the arc flash and surge protection systems described herein may be applicable to many different types of systems that may be susceptible to overvoltage, overcurrent, and/or arc fault conditions. For example, medium and/or low voltage distribution to control and distribute single-phase or multi-phase electrical power may utilize electrical surge and lightning protection systems as described herein. In some embodiments, a switchgear cabinet 60 may include an arc flash, overvoltage, overcurrent, and surge protection system 100 configured therein to protect the equipment 50, switchgear cabinet 60, and other components included therein and/or personnel close to the switchgear cabinet 60.

Brief reference is now made to Figure 4, which is a block diagram illustrating an arc flash, overvoltage, overcurrent, and overload protection system according to some embodiments of the present invention. As illustrated, a three-phase line can be connected to and supply power to one or more transformers 66, which in turn can supply three-phase power to a main circuit breaker 68. The three-phase power can be provided to one or more distribution panels. . 62. As illustrated, the three voltage lines of three-phase electrical power may be designated L1, L2, and L3, and a neutral line may be designated N. In some embodiments, the neutral line N may be conductively coupled to an outlet. of Earth.

Some embodiments include an arc flash, overvoltage, overcurrent and overload protection system 100 connected between the phase lines L1, L2 and L3, and neutral (N). The electric arc, overvoltage, overcurrent and overload protection system 100 can protect other installation equipment, such as the distribution panel 62 among others. In some embodiments, the arc flash, overvoltage, overcurrent, and overload protection system 100 may be coupled to and/or receive one or more signals from an arc flash detection system 64 that may be in a distribution panel 62 and/or other equipment in the facility.

As mentioned above, an arc flash, overvoltage, overcurrent, and overload protection system 100 may be implemented in a system corresponding to power distribution switchgear 60 that is configured to distribute multiphase electrical power. For example, reference is now made to Figure 5, which is a schematic diagram depicting a circuit including an arc flash and overload protection system in a three-phase switchgear cabinet according to some embodiments of the present invention. As illustrated, a three-phase line may be connected to and supply power to one or more transformers 66, which in turn may supply three-phase power to a main circuit breaker 68 in switchgear cabinet 60. Within switchgear cabinet 60, the Three-phase electrical power may be provided for one or more distribution panels 62 which may or may not be within switchgear cabinet 60. As illustrated, the three voltage lines of three-phase electrical power may be designated L1, L2, and L3 and one neutral line may be designated N. In some embodiments, the neutral line N may be conductively coupled to a ground.

In some embodiments, the arc flash, overvoltage, overcurrent, and overload protection system 100 may include a toggle device 102 operable to prevent an overvoltage condition by generating a low-resistance path from the three voltage lines L1, L2, L3 to the neutral line N. Although some embodiments are described herein with reference to an overvoltage condition, such embodiments may also refer to an overcurrent condition which may or may not be the result of an overvoltage condition. Some embodiments envision that the lever device may be actuated by a drive circuit 106.

As illustrated, toggle device 102 may include a surge protection module 120 corresponding to each of the three phases L1, L2, and L3. Each overvoltage protection module 120 may include two thyristors ( eg, TH5 and TH6) that are electrically coupled in parallel with each other, but with opposite polarities. Put another way, an anode of a first thyristor ( eg, TH5) of the thyristor pair can be coupled to a cathode of the second thyristor ( eg, TH6) of the thyristor pair and a cathode of the first thyristor (TH5) of the pair. of thyristors can be coupled to the anode of the second thyristor (TH6) of the pair of thyristors. In this way, when the thyristors are energized to be in a conducting state, each half of an AC waveform can be conducted from phase to neutral.

In some embodiments, a surge protection module 120 may include a circuit of a resistor R and a capacitor C arranged in series with each other, such that the resistor-capacitor series RC is connected in parallel with the two thyristors ( for example , TH5 and TH6). Although described and illustrated as a single resistor R and capacitor C, embodiments may include more than one resistor and/or more than one capacitor to achieve the desired resistive and/or capacitive performance, but also to use more R and C for redundancy. , since the operation of this circuit can be important to avoid false triggering of the thyristors. The snubber circuit can slow down a rate of change of voltage (dV/dt) that could otherwise cause false triggering of the thyristor. For example, in the absence of the RC snubber circuit, the thyristor may be driven by electrical noise that is unrelated to an actual overvoltage condition. Capacitor C can reduce the rate of change of voltage (dV/dt) together with resistor R. Inductance L and resistor R can limit the inrush current from the high capacitance value of capacitor C when the circuit is energized.

Some embodiments provide that an inductor L is arranged in series with the pair of antiparallel connected thyristors. The inductor L can limit a rate of change in current (di/dt) through the thyristors, which could otherwise damage the thyristors. Also, L, combined with the RC snubber circuit, reduces the rate of change of voltage (dV/dt) across the thyristors in the event of an overvoltage generated in the power system. In this way, an automatic actuation of thyristors can be prevented.

Some embodiments envision that in a three-phase power system, a toggle device 102 includes three surge protection modules 120 that can be coupled from respective phase conductors L1, L2, and L3 to a neutral N. In some embodiments, each One of the surge protection modules 120 is a modular component that includes all the functional components thereof in a single assembly. Some embodiments provide that multiple ( eg, three in a three-phase power system) surge protection modules 120 can be configured as a single assembly that includes the components and functionality for surge protection for all phases in a single assembly.

Some embodiments include surge protection devices (SPDs) 104. As illustrated, each of the SPDs 104 may be connected between the respective ones of LI, L2 and L3, and neutral (N). The use of the SPD can protect the lever device thyristors during lightning events and/or transient overvoltage conditions, as well as protect other equipment in the installation. Additionally, SPDs can be used to protect all equipment in case of prolonged surges. However, such a condition can force the SPD to carry a limited current for an extended period of time, which can result in the SPD overheating and possibly failing (depending on the energy-withstanding capabilities that the SPD can absorb and the level and duration of the overvoltage condition). Such an event can be addressed by actuation of the toggle device. A typical operating voltage of an SPD 104 in the present example may be approximately 400V (for 690V L-L systems). In this sense, the SPDs 104 will each function as an insulator and therefore will not conduct current during normal operating conditions. In some embodiments, the operating voltage of the SPDs 104 is sufficiently higher than the normal line-to-neutral voltage to ensure that the SPD 104 will continue to function as an isolator even in cases where the system voltage increases due to overvoltage conditions. that may arise as a result of a power loss or other power system problems.

In the event of an overload at, say, L1, the power system's load device protection may need to provide a current path to ground for the excess current from the overload. Overloading can cause a transient overvoltage between L1 and N. Since the overvoltage significantly exceeds the operating voltage of SPD 104, SPD 104 will become conductive, allowing excess current to flow from L1 through SPD 104 along neutral n

Once the overload has been driven to N, the overvoltage condition ends and the SPD 104 becomes non-conductive again. However, in some cases, one or more SPDs 104 may begin to allow leakage current to be conducted even at voltages that are lower than the SPDs 104's operating voltage. measure using, for example, current transformers. 105 that can provide leakage current values to the drive circuit 106.

An arc flash detection system 64 can be configured to detect an electrical arc within the switchgear cabinet 60 using one or more sensors and/or types of sensors including photosensors, pressure sensors, and/or current transformers, among others. The arc flash detection system can provide an arc flash detection (AFD) signal to the drive circuit. 106.

The drive circuit 106 can receive inputs corresponding to the line voltages L1, L2, L3, the line currents I1, I2, I3, the SPD leakage currents Is1, Is2, Is3, and the arc detection signal. electric AFD. As described in more detail below, drive circuit 106 may, in response to a fault circumstance, cause toggle device 102 to turn on, thus providing a low-resistance current path from lines L1, L2, L3 to neutral N, cause main breaker 68 to trip and/or cause SPDs to start driving. In some embodiments, drive circuit 106 may further generate and/or transmit an alarm signal to one or more other types of monitoring, recording, or alarm equipment.

Some embodiments provide that the drive circuit 106 is powered by a drive circuit power source 65, such as a single phase AC power supply and/or a DC power supply. Some embodiments envision that the drive circuit power source 65 may be coupled to the drive circuit 106 through one or more circuit breakers or circuit breakers 67 and thus may be protected by SPDs 104.

Reference is now made to Figure 6 , which is a schematic block diagram illustrating a drive circuit as briefly described above with respect to Figure 5, in accordance with some embodiments of the present invention. In some embodiments, a drive circuit 106 may include a power source and voltage hold circuit 166, which may receive single-phase AC power and/or DC power to power the drive circuit. The power supply and voltage hold circuit 166 may include a voltage hold circuit that may provide power to the circuit. for at least 100 milliseconds after a condition that removes the availability of electrical power received from the drive circuit power source 65.

In this way, even with a loss of drive circuit power due to a failure in another part of the circuit, the power supply and voltage hold circuit 166 maintain enough voltage for the drive circuit 106 to operate until the circuit breaker is capable of tripping. For example, during this period, drive signals to all thyristors may be continuously maintained to keep the thyristors in a conducting state. Therefore, the thyristors can be kept in a conductive state until the main circuit breaker 68 is actuated. Alternatively, if a drive signal to the thyristors is lost, the thyristors will only allow a very limited current flow through them, which can cause arcing to restart.

Brief reference is now made to Figure 7, which is a schematic block diagram illustrating a power source and voltage hold circuit 166 as discussed with reference to Figure 6 above. In some embodiments, the power supply and voltage holding circuit 166 is configured to receive electrical power as a single-phase alternating current (AC) power supply that includes a voltage line L ^p and a neutral line N ^p . In such embodiments, the received electrical power may be converted from AC to direct current (DC) using an AC-DC rectifier unit 180. The resulting DC power may be smoothed using a smoothing capacitor 182.

DC power may be provided to a voltage holding circuit 184 which may include a holding resistor Rh that is connected in parallel with a holding diode Dh. The parallel combination of holding resistor Rh and holding diode Dh can be connected in series with a holding capacitor Ch. Some embodiments provide that the circuit Rh, Dh, Ch is connected between the DC power line and the DC power line. ground or neutral. In some embodiments, the anode of the holding diode Dh is connected to the DC power line and the cathode of the holding diode Dh is connected to the holding capacitor Ch, the other terminal of which is connected to ground or neutral.

The power supply and voltage holding circuit 166 may include several different isolated DC-DC converters 186. For example, in the context of a three-phase system, an isolated DC-DC converter 186-1 may be provided. to supply voltage (Vs, S) to a common driver in each of three different thyristor drive circuits 168-1, 2, 3. In addition, three isolated DC-DC converters 186-2, 3, 4 can be provide for supplying voltage (Vs1, S1; Vs2, S2; Vs3, S3) to the respective thyristor drive circuits 168-1,2, 3, respectively.

Brief reference is now made to Figure 8 , which is a block diagram illustrating an isolated DC-DC converter as discussed with reference to Figure 7 above. An isolated DC-DC converter 186 may receive a DC input voltage Vin to an inverter 191, which is configured to convert the DC input voltage to an AC voltage. The AC voltage may be provided to isolation transformer 192, which may produce a corresponding AC output that is conductively isolated from the input AC voltage that is received from inverter 191. In some embodiments, isolation transformer 192 may include a 1:1 coil winding ratio so that the AC output voltage is at the same voltage level as the AC input voltage received by the isolation transformer. Some embodiments provide that the winding ratio of the isolation transformer coil 192 is not 1.0 and therefore the AC output voltage may have a different voltage level than the AC input voltage received by the isolation transformer. 192. The AC output voltage of the isolation transformer 192 may be received by a rectifier 193, which is configured to convert the AC voltage to a DC output voltage.

Referring to Figure 6 , in some embodiments, drive circuit 106 may include interface circuit 164 that is configured to receive inputs from various sensors and provide data corresponding to the received inputs to a microcontroller 162. For example, circuit interface 164 can receive inputs corresponding to: the voltages of the phase power lines L1, L2, L3 and the neutral N; an AFD arc flash alarm signal from the arc flash detection system 64; current flow in the phase power lines I1, 12, 13; current flow through the SPDs Is1, Is2, Is3; and/or temperature of the SPDs Ts1, Ts2, Ts3, among others.

Some embodiments envision that the microcontroller 162 may process the received inputs and generate drive signals to one or more thyristor drivers 168-1, 2, 3 to drive the thyristors into a conducting mode. In some embodiments, the microcontroller may further generate a drive signal TCB to the main circuit breaker. 68. Some embodiments envision that the microcontroller generates an alarm signal that may be provided to local and/or remote locations that may be monitored and/or may include supervisory control and data acquisition (SCADA). In some embodiments, the alarm signal is provided to a remote visual and/or audible annunciator.

The microcontroller 162 may drive the thyristors based on a variety of causes and/or events. For example, an arc flash may trigger an arc flash signal to be sent to microcontroller 162 from arc flash detection system 64. A system overvoltage condition corresponding to one or more lines having a voltage that exceeds a predetermined threshold for a predetermined period of time can cause the microcontroller to drive the thyristors. An overcurrent condition on one or more lines in which the current exceeds a predetermined current threshold for a predetermined period of time can cause the microcontroller to drive the thyristors.

In some embodiments, overheating of the surge protection devices 104 in which a temperature of the SPDs exceeds a predetermined temperature threshold for a predetermined period of time, may cause the microcontroller to drive the thyristors. Also, a short circuit can be detected when a drop in voltage of any phase line and a corresponding increase in current of that phase line can cause the microcontroller to drive the thyristors.

Some embodiments envision that a detected end of life of an SPD may cause the microcontroller to drive the thyristors. In some embodiments, such an SPD may include a combined metal oxide varistor (MOV) and/or MOV/GDT (gas discharge tube). Such a condition can be determined by a voltage drop in a phase line and a current increase in the corresponding SPD.

In some embodiments, the microcontroller may be configured to actuate the surge protection device only when specific combinations of conditions and/or events occur with or without restrictions on the time interval between the conditions and/or events.

In some embodiments, thyristor drivers 168-1, 2, 3 may receive a drive signal from microcontroller 162 and provide control signals to corresponding pairs of thyristors to cause the respective thyristors to change from a substantially non-conductive state to a non-conducting state. driver state. For example, brief reference is now made to Figure 9, which is a schematic block diagram illustrating a thyristor drive circuit 168-1 as discussed above with reference to Figure 6.

Each of the thyristor drive circuits 168 may be the same and may function to drive a pair of thyristors corresponding to a specific phase line. As such, Figure 9 addresses one of the thyristor circuits of Figure 6, namely 168-1, which corresponds to the thyristors connected to the phase line L1. Common lead 172 may be powered by voltage lines Vs and S which are provided from the power supply and voltage hold circuit 166 and which are provided to common lead 172 from each of the other thyristor drive circuits 168. -2, 3. Common lead 172 changes state to provide a thyristor drive signal TH1 responsive to drive signal T1 from microcontroller 162. Thyristor 1 changes to a conducting state in response to the state change of TH1 and remains in a conducting state while TH1 is activated. In the case of thyristor 1, the reference point C1 is the neutral line N.

The opto driver 170 may be powered by voltage lines Vs1 and S1 which are provided from the power supply and voltage hold circuit 166. In contrast to the DC voltage circuit Vs and S, the voltage lines Vs1 and S1 they are not provided to other thyristor circuits 168-2, 3. Opto lead 170 changes state to provide a thyristor drive signal TH2 responsive to drive signal T2 from microcontroller 162. Thyristor 2 changes to a conducting state in response to the state change of TH2 and remains in a conducting state while TH2 is activated. In the case of thyristor 2, the reference point C2 is the phase line L1. The phase voltage reference point is one reason to use an opto driver to isolate the output.

Referring to Figure 6 , the drive circuit drives all 6 thyristors at the same time and maintains the drive state for at least 100 milliseconds while at the same time power is supplied to the drive circuit through the power supply and circuit. voltage hold 166. In addition, while the thyristors are being driven, the drive circuit may provide a drive signal to the main circuit breaker 68 and an alarm indicating failure of the fault. In some embodiments, the alarm may also include data corresponding to a cause of the failure event.

Brief reference is now made to Fig. 10, which is a schematic diagram representing a circuit including an arc flash, overvoltage, overcurrent, and overload protection system in a three-phase switch cabinet according to some other embodiments of the present invention. As illustrated, the embodiments according to Figure 10 differ from those described above with respect to Figure 5 in that the toggle device 102 includes one bidirectional thyristor for each phase to neutral rather than two complementary unidirectional thyristors for each phase. Some embodiments envision that the bidirectional thyristors each rely on four control wires to provide a drive signal to them. Other features of Figure 10 are substantially similar to those discussed above with respect to Figure 5 and thus will not be repeated.

Reference is now made to Figure 11, which is a schematic diagram representing a circuit including an arc flash, overvoltage, overcurrent, and overload protection system in a three-phase switchgear cabinet according to some other embodiments of the present invention. As illustrated, the embodiments according to Figure 11 differ from those described above with respect to Figure 5 in that the toggle device 102 includes the thyristors and the SPDs 104. In some embodiments, one of the SPDs 104 is connected in the device lever 102 in parallel with the thyristor, RC and/or RLC circuits that are connected from each phase to neutral. Some embodiments envision that the SPDs 104 are metal oxide varistors (MOVs) and/or combined MOV/GDTs. In some embodiments, the MOVs may be thermally fused to prevent overheating of the MOV in the event of increased leakage currents, which may be a typical occurrence when an overvoltage condition exists in the circuit. the power system. In this regard, the drive circuit 106 may monitor the temperature rise and/or the thermal fuse and/or the current through the MOV to indicate whether the MOV has not shorted. In response to such conditions, the thyristors can be triggered rapidly to prevent further damage to the entire device. Some embodiments envision that the thermal fuse may be sufficient to interrupt leakage currents when the MOV has not failed to short, to prevent overheating of the device. Other features of Figure 10 are substantially similar to those discussed above with respect to Figure 5 and thus will not be repeated. To further reduce the overvoltage that could be applied to the thyristors, additional MOVs could be used in parallel to the snubber circuit (RC).

Reference is now made to Fig. 12, which is a schematic diagram showing a circuit including an arc flash, overvoltage, overcurrent, and overload protection system in a three-phase switch cabinet according to some other embodiments of the present invention. As illustrated, the embodiments according to Figure 12 differ from those described above with respect to Figure 5 in that the toggle device 102 is configured to connect phase to phase rather than phase to neutral. Specifically, a thyristor and an RLC circuit are connected from each phase to another phase so that toggle device 102 can operate without driving excess current to a neutral line N. Also, SPDs 104 are connected from phase to phase. to provide surge protection for one phase relative to the other phases. In some embodiments, toggle device 100 includes a single thyristor which may be a single directional thyristor. Other features of Figure 10 are substantially similar to those discussed above with respect to Figure 5 and thus will not be repeated.

As used herein, "monolithic" means an object that is a single unitary piece formed or composed of a material without joints or seams.

Referring to Figures 13-23, a lever system 200 and connector module 290 according to embodiments of the invention are shown therein. Lever system 200 corresponds to and is an implementation of lever system 102 of Figure 5. Connector module 290 corresponds to and is an implementation of a connector that can be connected between lever system 102 and drive circuit 106 as shown. illustrated in Figure 3.

Referring to Figure 13, system 200 includes three line conductors L1B, L2B, and L3B (electrically connected to lines L1, L2, and L3, respectively, of Figure 5), a neutral conductor NB (electrically connected to the neutral line N of Figure 5) and three lever modules 210(1), 210(2), and 210(3) according to embodiments of the invention and each corresponding to a respective one of the modules 120 of Figure 3. conductors L1B, L2B, L3B, NB can be metal plates or substantially rigid busbars, for example. The conductors L1B, L2B, L3B, NB can be mounted in an electrical switchgear cabinet 60, for example. Lever modules 210(1), 210(2), and 210(3) are electrically connected to connector module 290. Lever modules 210(1), 210(2), and 210(3) each connect electrically and mechanically the neutral conductor NB with one of the respective line conductors L1B, L2B, L3B.

In some embodiments, the conductors L1B, L2B, L3B, NB are rigid busbars and are fixed and rigidly connected by modules 210(1), 210(2), 210(3) to collectively form a substantially rigid unitary assembly or device. 203 (Figure 13).

Referring to Figures 14-21, lever module 210(3) is shown therein. Lever modules 210(1), 210(2), and 210(3) may be substantially identical in construction and therefore only lever module 210(3) will be described in detail below, it being understood that this description also applies to the other lever modules 210(1), 210(2). In this specification, the numeral 210 is used to describe each of the three lever modules 210(1), 210(2), 210(3) generally.

The 210(3) module includes a plastic sleeve 212, a metal base busbar 214, fasteners 215, a coil assembly 220, an internal circuit board assembly 230, a signal cable 232, and two assemblies or thyristor units 201, 202.

Thyristor units 201 and 202 each include a thyristor 270. Thyristor 270 in unit 201 corresponds to thyristor TH6 of Figure 5 and thyristor 270 in unit 202 corresponds to thyristor TH5.

A central through hole 214B and external through holes 214A are defined in bus bar 214 (FIG. 16). Holes 214A may be countersunk or recessed to fully receive bolt heads 217. According to some embodiments, bus bar 214 is formed of aluminum. According to some embodiments, bus bar 214 is unitary and, in some embodiments, monolithic.

Cover 212 and busbar 214 form a module housing that defines a closed cavity 212A within which coil assembly 220, internal circuit board assembly 230, signal cable 232, and drive units. lever 201,202 are contained. Signal cable 232 extends out of cover 212 through hole 212B and into connection module 290.

Cover 212 may be formed of a dielectric or electrically insulating material that has high melting and burning temperatures. In some embodiments, cover 212 is formed of a material that offers good moisture resistance. In some embodiments, cover 212 is formed of a polymeric material and, in some embodiments, a silicone compound or polybutylene terephthalate (PBT).

A filler material 218 (FIG. 14) fills the volume within the cavity not occupied by components 220, 230, 232, 201, 202. Filler material 218 may be a dielectric or electrically insulating material that has high melting and burning temperatures. In some embodiments, the filler material is formed of a polymeric material, and in some embodiments, includes a material selected from the group consisting of molten epoxy resin.

Coil assembly 220 (FIGS. 14 and 16-18) includes an electrically conductive coil member 222, an electrically conductive bus bar 224, an electrically conductive terminal member 226, an electrically insulating sheet 227, an electrically insulating casing 228, coupling bolts 229A and coupling bolts 229B.

Coil member 220 corresponds to coil L (FIG. 5). Coil member 220 includes a coil body 222A, a spirally extending coil strip 222C defining a spiral coil channel 222B, and a mating extension 222D. Threaded holes 222E extend axially through extension 222D and through holes 222F extend axially through body 222A.

According to some embodiments, coil member 220 is formed of metal, and in some embodiments, it is formed of aluminum. According to some embodiments, coil member 220 is unitary and, in some embodiments, monolithic.

End member 226 includes a body 226A, a coupling extension 226B, and an end post 226C. Holes 226E extend axially through extension 226B. A threaded hole 226D extends axially in post 226C. Terminal member 226 is electrically and mechanically connected to coil member 220 by screws 229B, which extend through holes 222E, 226E. Insulating sheet 227 is interposed between body 226A and body 222A to prevent or inhibit direct flow of electrical current between them.

According to some embodiments, the terminal member 226 is formed of metal, and in some embodiments, it is formed of aluminum. According to some embodiments, the terminal member 226 is unitary and, in some embodiments, monolithic.

Bus bar 224 includes a body 224A that is substantially flat on its upper side and has spacers 224B protruding from its lower side. Bolt holes 224C extend axially through body 224A and spacers 224B. Fasteners 229A extend through holes 224D and into coil body 222A to secure the upper face of busbar 224 in mechanical and electrical contact with coil body 222A.

According to some embodiments, bus bar 224 is formed of metal, and in some embodiments, it is formed of aluminum. According to some embodiments, bus bar 224 is unitary and, in some embodiments, monolithic.

Casing 228 includes an outer casing portion 228A and a spacer wall portion 228B. Outer skin portion 228A partially surrounds and encases components 222, 224, 226, 227. Bolt holes 228C are defined in portion 228A in alignment with holes 222F. Terminal post 226C protrudes through post hole 228D and above casing 228. Part of spacer wall 228B fills coil channel 222B between adjacent coil strip windings 222C.

Housing 228 may be formed of a dielectric or electrically insulating material that has high melting and burning temperatures. In some embodiments, housing 228 is formed of a polymeric material. In some embodiments, housing 228 includes an epoxy. In some embodiments, housing 228 includes a material selected from the group consisting of epoxy adhesive and/or molded epoxy resin or silicone elastomer. In some embodiments, the shell 228 is monolithic. In some embodiments, the shell 228 includes a material selected from the group consisting of epoxy adhesive and/or molded epoxy resin that is itself covered by an outer layer of a different material.

Outer shell layer 223 may be formed of a different material than shell 228 to provide complementary properties. In some embodiments, outer shell layer 223 is formed of a material that provides increased moisture resistance compared to shell material 228. In some embodiments, outer shell layer 223 is formed of a silicone compound or PBT. The 223A O-rings (made of the same or similar material as the 265A, 265B O-rings) prevent leakage of the epoxy used in liquid form (initially) to form the 228 housing.

Circuit board assembly 230 includes a substrate 230A ( eg, a PCB) and capacitor 230B, a pair of resistors 230C, 230D, a lead wire 230E, and a lead carrier 230F mounted thereon. Capacitor 230B corresponds to capacitor C (Figure 5). Resistors 230C, 230D correspond to resistor(s) R (FIG. 5). Capacitor 230B is electrically connected to bus 224 by lead 230E and resistors 230C, 230D are electrically connected to bus 214 by lead support. 230F. Resistors 230C, 230D and the capacitor of a snubber circuit as described in more detail below.

With reference to Figures 16 and 19-21, the lever unit 201 is shown therein. Lever units 201, 202 may be substantially identical in construction and therefore only lever unit 201 will be described in detail below, it being understood that this description also applies to lever unit 202.

The lever unit 201 has a longitudinal axis A-A (FIG. 20). Lever unit 201 includes a first electrode or housing 240, a piston-shaped second electrode 250, a thyristor 270 between housing 240 and electrode 250, and other components as discussed in more detail below.

Referring to Figures 19 and 20, housing 240 has an end electrode wall 242 and a cylindrical side wall 244 extending from electrode wall 242. Side wall 244 and electrode wall 242 form a chamber or cavity. 241 communicating with an opening 246. A threaded hole 249 extends axially in the electrode wall 242. An opening or cable port 248 extends through the side wall 244 and has an enlarged recess 248A at its outer opening.

Electrode 250 has a head 252 disposed in cavity 241 and an integral shaft 254 projecting out through opening 246. Thyristor 270 is disposed in cavity 241 between and in contact with each of the electrode walls. 242 and head 252.

Moving on to the construction of the lever unit. 201 in more detail, the lever unit 201 further includes spring washers 262, flat washers 264, an insulating member 266, an end cap 268, a retaining clip 267, O-rings 265A, 265B, and a grommet 280.

Electrode wall 242 of housing 240 has a substantially flat inwardly facing contact surface 242A. A locator feature or post 247 projects upwardly from contact surface 242A. An annular groove 243 is formed on the inner surface of sidewall 244. According to some embodiments, housing 240 is formed of aluminum. However, any suitable electrically conductive metal can be used. According to some embodiments, the shell 240 is unitary and, in some embodiments, monolithic. Casing 240 as illustrated is cylindrical in shape, but may have a different shape.

As best seen in Figure 20, head 252 of electrode 250 has a substantially flat contact surface 252A oriented to contact surface 242A of electrode wall 242. A threaded hole 255 is formed in the end of shaft 254 for receive bolt 215 to secure bus bar L3B to electrode 250. A sideways opening annular groove 254D is defined on axis 254.

According to some embodiments, electrode 250 is formed of aluminum, and in some embodiments, housing sidewall 244 and electrode 250 are both made of aluminum. However, any suitable electrically conductive metal can be used. According to some embodiments, electrode 250 is unitary and, in some embodiments, monolithic.

An annular space G1 is defined radially between head 252 and the nearest adjacent surface of sidewall 244. According to some embodiments, space G1 has a radial width in the range of about 5 to 15 mm.

Housing 240, insulating member 266, and end cap 268 collectively define a closed chamber 245 containing thyristor 270.

Thyristor 270 includes a body 272 and an anode 274 and cathode 276 at axially opposite ends of body 272. It will be appreciated that in Figure 14 the internal structure and components of the thyristors are not shown in detail. Anode 274 and cathode 276 have substantially planar contact surfaces 274A and 276A, respectively. Thyristor 270 is interposed between contact surfaces 242A and 252A such that contact surface 274A mates with contact surface 242A and contact surface 276A mates with contact surface 252A. As described below, head 252 and wall 242 are mechanically biased against thyristor 270 to ensure tight and smooth engagement between the mating interfaces. Locator post 247 of housing 240 is located in a complementary locator socket 277 formed on contact surface 276A.

Thyristor 270 further includes a control gate or terminal 278A and a reference terminal 278B. For example, as illustrated in Figure 5, an input to the gate or control terminal 278A of the thyristor labeled TH5 therein may correspond to the signal TH5 from the drive circuit 106. Similarly, a reference connection to a reference terminal 278B of thyristor TH5 may correspond to reference C5 from drive circuit 106.

Referring to Figure 20, grommet 280 is attached to cable port 248 and two signal cables 232A, 232B extend through cable port 248 and grommet 280 and into chamber 245. Cable 232A is electrically terminated at control terminal 278A and cable 232B is electrically terminated at reference terminal 278B.

The grommet 280 includes a fitting 282 that is secured in the cable port 248. The fitting 282 has a cylindrical body 282A, a flange 282B, and a through hole 282C. Body 282A is located in cable port 248 and flange 282B is located in recess 248A. Fitting 282 can be secured in place with adhesive 284, for example. In some embodiments, adhesive 284 bonds body 282A and flange 282B directly to the cable port wall 248.

The grommet 280 further includes a sealing plug 286 in the hole 282C. Sealing plug 286 surrounds cables 232A, 232B, attaches to cables 232A, 232B and fitting 282, and continuously fills the radial space between cables 232A, 232B and fitting 282 and seals over cables 232A, 232B. In this manner, sealing plug 286 serves to mechanically retain or secure cables 232A, 232B in port 282C (providing strain relief) and to completely seal, plug, or close port 282C ( eg , hermetically).

Sealing plug 286 may be formed of a rigid material that has high melting and burning temperatures. In some embodiments, sealing plug 286 is formed of a polymeric material. In some embodiments, sealing plug 286 is a hardened or cured resin. In some embodiments, sealing plug 286 includes an epoxy. In some embodiments, sealing plug 286 includes an epoxy adhesive or cast epoxy resin.

Fitting 282 may be formed of a rigid material that has high melting and burning temperatures. In some embodiments, fitting 282 is formed of a polymeric material. In some embodiments, fitting 282 is formed of Nylon-66 (PA-66) or equivalent.

A grommet 280 may also be provided to seal and penetrate cable 232 through cover 212 (FIG. 15).

Spring washers 262 surround shaft 254. Each spring washer 262 includes a hole that receives shaft 254. Lower spring washer 262 abuts the top face of head 252. According to some embodiments, the clearance between the hole of the spring washer and shaft 254 is in the range of about 0.015 to 0.035 inches. The spring washers 262 may be formed of a resilient material. According to some embodiments and as illustrated, the spring washers 262 are spring steel Belleville washers. While two 262 spring washers are shown, more or less can be used. The springs may be provided in a different stack arrangement, such as in series, in parallel, or in series and parallel.

Flat metal washers 264 are interposed between spring washer 262 and insulating ring 266 with shaft 254 extending through holes formed in washers 264. Washers 264 serve to distribute the mechanical load of the spring washer. top 262 to prevent spring washer 262 from cutting insulating ring 266.

Insulating ring 266 overlaps and abuts washer 264. Insulating ring 266 has a main body ring 266A and a cylindrical upper flange or collar 266B extending upwardly from main body ring 266A. A hole 266C receives the shaft 254. According to some embodiments, the clearance between the hole 266C and the shaft 254 is in the range of about 0.025 to 0.065 inches. An upwardly and outwardly opening peripheral groove 266D is formed in the upper corner of the main body ring 266A.

Insulating ring 266 is preferably formed of a dielectric or electrically insulating material that has high melting and burning temperatures. Insulating ring 266 may be formed of polycarbonate, ceramic, or a high temperature polymer, for example.

End cap 268 overlies and rests on insulating ring 266. End cap 268 has a hole 268A that receives shaft 254. According to some embodiments, the clearance between hole 268A and shaft 254 is in the range of about 0.1 to 0.2 inches. End cap 268 may be formed of aluminum, for example.

Clip 267 is in the form of a truncated, elastic ring. Clip 267 is partially received in slot 243 and extends partially radially inwardly from the interior wall of housing 240 to limit outward axial displacement of end cap 268. Clip 267 may be made of spring steel.

O-ring 265A is positioned in groove 254 so that it is trapped between shaft 254 and insulating ring 266. O-ring 265B is positioned in groove 266D such that it is trapped between insulating member 266 and sidewall 244. When installed, the O-rings 265A, 265B are compressed so that they press against each other and form a seal between adjacent interface surfaces. In a surge event, by-products such as hot gases and fragments from thyristor 270 may fill or spread into cavity chamber 245. These by-products may be limited or prevented by O-rings 265A, 265B from escaping lever unit 201. through the opening of the housing 246.

O-rings 265A, 265B may be formed of the same or different materials. According to some embodiments, the O-rings 265A, 265B are formed of a resilient material, such as an elastomer. According to some embodiments, the O-rings 265A, 265B are formed of rubber. O-rings 265A, 265B may be formed of a fluorocarbon rubber such as VITON™ available from DuPont. Other rubbers such as butyl rubber can also be used. According to some embodiments, the rubber has a durometer of between about 60 and 100 Shore A.

Electrode head 252 and casing wall 242 are persistently biased or loaded against thyristor 270 along a DC clamping or load axis (Figure 20) to ensure tight and uniform coupling between thyristor contact surfaces. 276A, 274A and surfaces 242A, 252A. This aspect of unit 201 can be appreciated by considering a method according to the present invention for assembling unit 201, as described below.

Wires 232A, 232B are secured in hole 282A of fitting 282 using sealing plug 286. In some embodiments, wires 278A, 278B are inserted into hole 282A, a liquid sealing material is introduced ( eg, poured or injected) into the hole of leads 232A, 232B, and the sealing material cures to form rigid sealing plug 286 on leads 232A, 232B.

Accessory 282 is secured in cable port 248 using adhesive 284. Cables 232A, 232B are connected to terminals 274A, 276A. In some embodiments, cables 232A, 232B are secured by sealing plug 286 prior to the step of securing fitting 282 in cable port 248.

O-rings 265A, 265B are installed in grooves 254, 266D. Thyristor 270 is positioned in cavity 241 such that contact surface 276A engages contact surface 242A. Electrode 250 is inserted into cavity 241 such that contact surface 252A engages contact surface 274A. Spring washers 262 slide on shaft 254. Washers 264, grommet 266, and end cap 268 slide on shaft 254 and over spring washers 262. A template (not shown) is used. or other suitable device to force end cap 268 downward, in turn biasing spring washers 262. While end cap 268 is still under jig load, clip 267 is compressed and inserted into the slot 243. Clip 267 is then released and allowed to return to its original diameter, after which it partially fills the slot and extends partially radially inward into cavity 241 from slot 243. Clip 267 and slot 243 therefore serve to maintain the load on the end cap 268 to partially bias the spring washers 262. The load from the end cap 268 on the insulating ring 266 and from the insulating ring to the spring washers 262 is transferred It in turn transfers to head 252. In this way, thyristor 270 is sandwiched (clamped) between head 252 and electrode wall 242.

When lever unit 201 is assembled, housing 240, electrode 250, insulating member 266, end cap 268, clip 267, O-rings 265A, 265B, and grommet 280 collectively form a housing unit or assembly. housing 249 containing the thyristor 270.

Lever module 210 can be assembled as follows according to the methods of the invention.

To construct coil assembly 220, busbar 224 is secured to coil member 222 using bolts 229A. Terminal member 226 is secured to coil member 222 using bolts 229B with insulating sheet 227 captured between terminal member 226 and coil member 222. Housing 228 is thereafter molded around and through this subassembly. . For example, in some embodiments, the subassembly is placed in a mold, the mold is then filled with liquid shell material ( for example, a liquid resin), and the material is then cooled or cured to form the rigid shell. 228. The hole regions 228C, 228D, 222F, 226D may be temporarily filled or plugged with mold features or the like to prevent liquid envelope material from filling these regions. Housing 223 is molded or fitted around housing 228. For example, housing 223 may be molded or co-molded around housing 228. Elastomeric O-rings 223A may be placed around terminal post 226C and rod spacers. collectors 224B.

The coil assembly 220 is secured to the electrode 240 of the lever unit 201 by a bolt 217 and to the electrode 250 of the lever unit 202 by a bolt 217. The heads of the screws 217 are located in the holes 228C of the 228 shell to provide a low, flat profile. The base busbar 214 is secured to the electrode 250 of the lever unit 201 by a bolt 217 and to the electrode 240 of the lever unit 201 by a bolt 217. The heads of the screws 217 are located in the holes 214A of base busbar 214 to provide a low, flat profile. Lead wires 230E and 230F are secured to busbar 224 and base busbar 214, respectively, by screws.

Cover 212 is installed over the above subassembly and attached to base busbar 214 by fasteners ( eg, screws), adhesives, and/or interlocking features, for example. Cable 232 (including cable pairs 232A, 232B from each of the lever units 201,202) is routed through opening 212B in cover 212. The remaining volume of cavity 212A is filled with filler material. 218. In some In embodiments, a liquid filler material is introduced ( e.g. , poured or injected through hole 214B) into cavity 212A, and then cured to form rigid filler material 218.

Connection module 290 (FIGS. 13 and 22) includes circuit(s) corresponding to an interconnection between lever system 102 and drive circuit 106. For example, some embodiments envision lever system 102 including three lever modules. 210(1), 210(2), and 210(3) (shown schematically as toggle module 120 in Figure 5) that include connections to activation circuit 106. Specifically, for example, each of the wires 232 may correspond to a respective one of the lever modules 210 and may correspond to the thyristor drive signals for each of the two lever units 201 within each lever module 210 and reference signals for each of the two lever units within of each lever module 210. The connection module 290 may include a surrounding enclosure 292, and multiple electrical contacts that are configured to provide connections to contacts on a mating connector. ing (not shown). In this way, the lever system 102 can be connected to the drive circuit 106.

To connect the lever modules 210(1), 210(2), 210(3) to the conductors L1B, L2B, L3B, NB, each of the line conductors L1B, L2B, L3B is mechanically and electrically connected to the member terminal 226 of a respective one of the lever modules 210(1), 210(2), 210(3) by a bolt 215, and the neutral conductor NB is mechanically and electrically connected to the base bus bars 214 of the modules of lever 210(1), 210(2), 210(3) by bolts 215.

In use, lever system 200 and lever modules 210(1), 210(2), 210(3) are made as described above for system 102 and three modules 120, respectively (FIG. 5).

When a trigger event occurs and the thyristors 270 of a module 210 conduct current between the lines connecting the module 210 ( ie, the neutral line N and the associated lines L1, L2, L3). As discussed above, the lever units 201, 202, and thus the thyristors 270 thereof, are oriented in opposite directions to conduct current in the respective AC directions. In the case of lever unit 202 of module 210, current flows sequentially through terminal post 226C, terminal extension 226B, coil member extension 222D, coil strip 222C, coil body coil 222A, bus bar 224, electrode 250 coupled to bus bar 224, thyristor 270, electrode 240 coupled to bus bar 214, and bus bar 214. In the case of lever unit 201, the current flows sequentially through bus bar 214, electrode 250, thyristor 270, electrode 240, bus bar 224, coil body 222A, coil strip 222C, extension 222D, extension 226B, and terminal post 226C.

The construction and configuration of the lever modules 210 provides a compact, modular, unit-packaged device that can be efficiently integrated into existing electrical equipment cabinets. The package provides a simple and convenient layout and features for connecting modules 210 to lines L1, L2, ^l 3, N ( eg via busbars L1B, L2B, L3B, NB).

Furthermore, the construction and configuration of the toggle modules 210 can provide the toggle modules 210 with increased strength and durability to withstand the physical effect (electromagnetic forces generated) of fault currents over an extended period of time and other electrical and electrical stresses. mechanics in service. Therefore, it can safely withstand the short-circuit event (avoid safety problems for personnel and any damage to the installation equipment, as well as to the entire installation itself) when it is actuated.

The toggle module 210 can function when actuated in two different ways: one to withstand the fault current for the period of time required to actuate the upstream main breaker, and a second (a different design than the first) that the thyristors 270 do not. they can withstand the fault current and fail shortly. The second option is attractive due to the lower power withstand capability of the thyristors used in the design. However, in such a case, the lever system 200 can generally only be actuated once, since after it is actuated, the system 200 is not recoverable and must be replaced. In the case where the thyristors 270 can withstand the fault current, two additional arrangements are usually required. One is that the added coil inductance 222 is used to eliminate the possibility of damaging the thyristors due to high di/dt during driving fault currents (it creates a hot spot on the inner surface of the thyristor disc). The coil impedance is also useful in allowing the snubber circuit 230B, 230C, 230D to prevent self-driving of the thyristor due to excessive dv/dt (reducing the dV/dt, which requires a certain impedance in the circuit; in some applications this could be part of the existing system impedance and allow the coil to be omitted). The second is that even in this case there should be arrangements using the same construction for the lever module 210 to resist damage in the event that the thyristor fails in a short - typical thyristor failure mode. Therefore, the lever module 210 configuration is highly beneficial, and in some cases mandatory, for both design implementations (lever module 210 strength and failure).

For example, when a module 210 is activated, a thyristor 270 itself may be damaged ( eg, as a result of carrying full fault current). However, the associated housing assembly 241 contains the damage ( eg, debris, gases, and immediate heat) within the lever unit 201, 202, so that the module 210 fails safely. Furthermore, the module components 210 surrounding the unit 201, 202 may also contain or buffer any heat or harmful products escaping from the unit 201, 202. In this way, the module 210 can prevent or reduce any damage to adjacent equipment ( eg , switchgear equipment in the cabinet) and injury to personnel. In this way, module 210 can improve the safety of equipment and personnel. This can be a very important feature, as the primary reason for using a toggle system, as described in this specification, is to protect equipment and personnel from arc flash hazards which are typically caused by insulation breakdown. between busbars or by faults in semiconductor devices (such as thyristors, IGBTs, etc.). Therefore, such a system may be of limited or no value if it creates the same harmful effects that it is used to resolve (dangerous failure of semiconductor devices).

The construction of the coil assembly 220, and in particular the housing 228, provides a robust and unitary component. The improved strength of coil assembly 220 is beneficial in resisting stresses that may be experienced and exerted by coil member 222, which is in series across the lines.

Filler material 218 may provide module 210 with enhanced strength. The filler material 218 can help contain the byproducts of thyristor destruction. The filler material 218 can thermally insulate and electrically isolate the electrical components of the module 210 from the environment ( eg , personnel and other equipment in the switchgear cabinet). Filler material 218 may also provide tamper resistance.

The grommet 280 provides strain relief for the cables 232A, 232B, and also serves to seal the cable port 248 to prevent or inhibit the expulsion of by-products of thyristor destruction through the cable port 248.

In some embodiments, the grommet 280 is constructed to allow rupture or failure of the grommet 248 in response to pressure in the chamber that exceeds a pressure threshold in a prescribed range. That is, the grommet 280 can serve as a pressure dependent valve. This can be a very important feature in case, for some reason, the toggle module 210 is overexposed to fault currents, beyond its specifications, and the grommet 280 functions as a pressure relief within the module 210 without creating hazards. significant ( i.e., it is a controlled way of relieving internal pressure by allowing smoke emission in a specific direction that could be controlled externally by guiding smoke emissions to a vent.

A failure of the grommet 280 can be observed without disassembling the lever unit 201,202. The valve function of the grommet 280 can be advantageously used to determine the maximum fault current and duration that the toggle module 210 can withstand, having as an indication only when the valve will open when the toggle unit 201,202 is being tested or classified ( used as a first indication that the crowbar module 210's fault current withstand capability is near its limits, rather than experiencing total damage to the entire module).

Electrical protection devices according to embodiments of the present invention ( eg, device 210) can provide a number of advantages in addition to those mentioned above. The devices can be formed to have a relatively compact form factor. The devices can be adapted for installation in place of similar type toggle devices not having a thyristor as described herein. In particular, the present devices may have the same length dimension as such prior devices. That depends on the fault current rating of the lever system, the duration of the fault current, and the mode of operation during actuation (resistance or fault). That determines the size of the thyristors 270 employed and thus the size and construction details of the lever modules 210 and the entire system.

According to some embodiments, the mating areas between each of the electrode contact surfaces ( eg, contact surfaces 242A, 252A) and the thyristor contact surfaces ( eg, contact surfaces 274A, 276A) are measured at least one square inch.

According to some embodiments, the polarized electrodes 240, 250 apply a load to the thyristor 270 along the C C axis in the range of 2,000 lbf and 26,000 lbf depending on their surface area.

According to some embodiments, the combined thermal mass of the housing 240 and electrode 250 is substantially greater than the thermal mass of the thyristor 270. As used herein, the term "thermal mass" means the product of the specific heat of the material(s). of the object ( for example, the thyristor 270) multiplied by the mass(es) of the material(s) of the object. That is, the thermal mass is the amount of energy required to raise one gram of the material(s) in the object by one degree centigrade times the mass(es) of the material(s) in the object. According to some embodiments, the thermal mass of at least one of the electrode heads 252 and the electrode wall 242 is substantially greater than the thermal mass of the thyristor 270. According to some embodiments, the thermal mass of at least one of the electrode heads 252 and electrode wall 242 is at least twice the thermal mass of thyristor 270, and, according to some embodiments, at least ten times greater. According to some embodiments, the combined thermal masses of head 252 and wall 242 are substantially greater than the thermal mass of the thyristor 270, according to some embodiments at least twice the thermal mass of the thyristor 270 and, according to some embodiments, at least ten times greater.

As discussed above, spring washers 262 are Belleville washers. Belleville washers can be used to apply relatively high loads without requiring substantial axial clearance. However, other types of biasing means may be used in addition to or instead of the Belleville washer(s). Suitable alternative loading means include one or more coil springs, wave washers or spiral washers.

According to further embodiments of the invention, the lever module 210 can be constructed with a single lever unit 201 or 202 ( i.e., the other lever unit 202 or 201 is omitted), so that the lever module thus formed conducts electrically only in one direction. Such modified toggle modules can be used in combined inverted pairs to provide toggle module functionality. 210.

According to further embodiments of the invention, the lever module 210 can be constructed with a single lever unit 201 or 202 ( i.e., the other lever unit 202 or 201 is omitted), but in such a way that the single lever unit remaining 201, 202 includes, instead of thyristor 270, a bidirectional thyristor that can operate in both directions. That is, when activated, the bidirectional thyristor will conduct current in both directions of alternating current. This lever module can be reduced in size and/or cost compared to the dual thyristor lever module.

According to further embodiments of the invention, lever module 210 may be constructed without coil 222.

Referring to Figure 23, a lever module 310 according to further embodiments of the invention is shown therein. Lever module 310 corresponds to lever module 210, except as described below. In Figure 23, the cover 212, the filler material 218, and the lever unit 201 are not shown, in order to provide a clearer view for the purpose of explanation. Lever unit 201 in lever module 310 is electrically connected to base busbar 214 and coil member 222 by bolts 217A and 217B as in lever module 210.

Lever module 310 includes an integral metal oxide varistor (MOV) device 288. Integrated MOV device 288 is electrically connected to terminal member 226 by track 289A (bypassing coil 222C) and to the base bus bar. 214 for a runway 289B. MOV device 288 is mounted on an electrically insulating substrate 288C between leads 289A, 289B. MOV device 288 includes a first plug wire that is in electrical contact with wire 289A and a second plug wire that is in electrical contact with wire 289B. The MOV internally includes a thermal link (thermal disconnect or thermal fuse) between the 288A lead and the MOV's single electrode. The other electrode of the MOV is connected to lead 288B. In addition, the connection between the 226 and MOV leader 288A, as well as the connection between the 214 busbar and the 288B conductor, is made using a busbar to allow the power line and ground connections to withstand the forces generated by the current conducted when the MOV conducts surge/lightning currents or fault currents from the power source. The lever module 310 can be used as a lever module in the lever device 102 of the system described above with reference to Figure 11 for example. An additional MOV could also be used, integrated on the 288C PCB - and connected in parallel to the two thyristors to reduce the overvoltage at their ends and avoid the maximum expected overvoltage that could lead to false triggering of the thyristor.

Reference is now made to Figure 24, which is a schematic diagram illustrating an arc flash, overvoltage, overcurrent, and overload protection system according to some embodiments of the present invention. Figure 24 may include elements that are described above with respect to at least Figure 5 and thus further description thereof may be omitted. In some embodiments, arc flash, overvoltage, overcurrent, and overload protection system 500 may protect the electrical system of a wind turbine generator from arc flash, overcurrent, and/or overload or lightning events. Some embodiments provide that the arc flash, overvoltage, overcurrent, and overload protection system 500 includes a toggle device 502 that is operable to prevent an overvoltage condition by generating a low-resistance path from the phase voltage lines L1, L2, L3 to neutral line N. Some embodiments envision that lever device 502 includes lever modules 520 that are connected between the corresponding phase voltage line L1, L2, L3 and neutral line N.

Some embodiments envision that each of the lever modules 520 may be connected to a current sensor 505 that may monitor the current flow of the corresponding phase line. In some embodiments, current sensor 505 may be separate from lever module 520 and/or lever device 502 while in some other embodiments current sensor 505 may be integrated into lever module 520 and/or lever device. lever 502.

Some embodiments include surge protection devices (SPDs) 104. As illustrated, each of the SPDs 104 may be connected between the respective ones of L1, L2, and L3, and neutral (N). Use of the SPD 104 can protect the thyristors of the crowbar 502 during lightning events and/or transient overvoltage conditions, as well as protect other equipment in the facility.

In some embodiments, toggle device 502 may be actuated by an arc flash drive circuit 506. As described above, an arc flash detection system 64 may be configured to detect an arc flash within switchgear cabinet 60 and provide an arc flash detection (AFD) signal to the arc flash drive circuit 506. In some embodiments, the arc flash drive circuit 506 may handle the drive and alarm signals from the toggle modules 520 and provide the outputs for actuation to one or more circuit breakers 68. Some embodiments envision that the arc-flash actuation circuit 506 may also provide indications corresponding to the state of each toggle module 520 and a cause of actuation of the toggle modules 520.

The arc flash, overvoltage, overcurrent, and overload protection system 500 may also include a threshold selector 510 that provides a signal to the arc flash drive circuit 506 to set the current threshold at which the arc flash drive circuit 506 causes toggle module 520 to activate.

In use and operation, under normal operating conditions, a lever module 520 may remain inactive and therefore not conduct current between phase lines L1, L2, L3 and the neutral line N. Normal operating conditions may include those where the phase line voltage is less than a specified threshold. For example, in some embodiments, the specific threshold may be approximately 1800 V peak, however, such embodiments are not limiting in that the threshold voltage may be more or less than 1800 V.

A toggle module 520 can be actuated in different ways depending on when a fault condition is detected. For example, lever module 520 may be actuated in a first manner during a start-up period and in a second manner during steady-state operation.

During a start-up period, such as within about 2 seconds or less from the start of a wind turbine or other generating device, lever module 520 may operate without a power source from arc drive circuit 506. In this regard, lever module 520 cannot be actuated by an alarm signal from arc flash detection system 64 since such system is generally not available for operation during a start-up period. In this way, the lever module 520 can be actuated automatically during the start-up period.

Reference is now made to Figure 25, which is a schematic block diagram illustrating a lever module as briefly described above with respect to Figure 24, in accordance with some embodiments of the present invention. Lever module 520 may include two thyristors TH1, TH2 that are connected antiparallel to each other and in series with an inductor L. As used herein, the term "antiparallel" may refer to a configuration in which the components they are connected in parallel with each other, but in a complementary arrangement with each other. For example, an anode terminal of a first component may be connected to a cathode terminal of a second component while the cathode terminal of the first component is connected to the anode terminal of the second component. In some embodiments, a resistor R and a capacitor C may be connected in series with each other and in parallel with thyristors TH1, TH2. Lever module 520 may further include lever actuation circuit 530 that is configured to provide an automatic actuation function within lever module 520. During a start-up period, lever actuation circuit 530 may be powered by current received from current sensor 505. For example, toggle module 520 can be actuated automatically once the current through the phase line is above the current threshold (I ^th ) for a period of more than 2ms In such cases, only lever module 520 that is connected to the corresponding phase line can be actuated.

Brief reference is now made to Figure 27, which is a graph illustrating voltage and current values during a fault condition in accordance with some embodiments of the present invention. Continuing with the previous example, at time t1 a fault current I reaches the threshold current I ^th . At time t2, in response to the fault current I exceeding the threshold current I ^th for a specified period of time, the lever module 520 begins to conduct the fault current thereby reducing the voltage for the remaining portion of that current. cycle at time t3 to approximately zero volts. If the fault persists during the second half of the cycle, then lever module 520 again conducts the fault current thus reducing the voltage for the remaining portion of that cycle.

Referring to Figure 25, some embodiments envision that each time the toggle module 520 is actuated a drive signal will be provided to the arc flash drive circuit 506. In some embodiments, the response time of the toggle module 520, from the time the overcurrent is detected, it can be less than about 1ms. In some embodiments, the response time may be less than about 500 gs. Some embodiments envision that the response time may be about 300 gs.

Reference is now made to Figure 26, which is a schematic block diagram illustrating a lever actuation circuit of the lever module as briefly described above with respect to Figure 25, in accordance with some embodiments of the present invention. Lever drive circuit 530 may receive a current signal from current sensor 505 at one or more step-up transformers 510, 512. Since the current signal and the output of step-up transformers 510, 512 may be a current signal (AC), the outputs of step-up transformers 510, 512 may be received by rectifiers 520, 522, respectively. Rectifiers 520, 522 can generate direct current (DC) signals that correspond to the current signal from current sensor 505.

Lever drive circuit 530 may also include variable reference signal generators 530, 532 that provide reference signals corresponding to the selected value of I ^th . Comparators 540, 542 may be configured to receive DC signals from rectifiers 520, 522, respectively, and reference signals from variable reference generators 532, 530. In response to one of the rectifier DC signals exceeding signal reference, the output state of the comparator changes from high to low, or vice versa. Lever actuation circuit 530 may include delay circuits 550, 552 that are configured to receive output signals from comparators 540, 542. In response to receiving a modified output from comparators 540, 542, the output of comparators delay circuits 550, 552 will switch after a given delay time. By providing the time delay, false triggering of the thyristors can be prevented and/or reduced. The output of the delay circuits 550, 552 may provide thyristor drive signals through diodes 588, 582 which cause the corresponding thyristors to turn on in a conducting state.

In some embodiments, the delay circuits 550, 552 may provide different reference voltage signals from each other. For example, delay circuit 550 may provide a positive voltage relative to the neutral line to drive thyristor TH1. Similarly, the delay circuit 552 can provide a positive voltage relative to the lower terminal of the inductor L ^th .

While the foregoing describes the automatic activation operation of the toggle drive circuit 530 during a start-up period, once the start-up period ends the normal operation of the toggle module 520 responds to the arc drive circuit. 506. Lever drive circuit 530 may receive a control voltage Vcc and ground in DC-DC converters 570, 572. In some embodiments, a first DC-DC converter 572 may provide a DC voltage that is capable of of driving the first thyristor TH1 and a second DC-DC converter 570 can provide a DC voltage that is capable of driving the second thyristor TH2. Lever drive circuit 530 may also receive an arc-flash detection signal at controller 580. In response, driver 580 may energize optical switches 560 and 562, causing DC voltages to be applied to thyristors TH1, TH2. through diodes 584, 588.

Reference is now made to Figure 28, which is a schematic block diagram illustrating a lever module arc drive circuit as briefly described above with respect to Figure 24, in accordance with some embodiments of the present invention. The arc drive circuit 506 may be supplied with a ground and an operating voltage Vcc, such as, for example, 24 V DC. A latch circuit 546 may receive and latch an arc-flash signal alert condition received from an arc-flash detection system 64. Some embodiments provide that the arc-flash drive circuit 506 includes a plurality of output drives 544. which can be used to provide a drive signal to one or more circuit breakers and/or alarms.

In some embodiments, the arc flash drive circuit 506 includes an array 548 that is configured to receive a discrete digital input from a threshold selector 510 and generate a current threshold value based on the value of the received digital input signal. Some embodiments envision that threshold selector 510 may be a rotary switch that provides a discrete digital signal, such as a two-bit binary signal. In such embodiments, different threshold selector 510 outputs may be 00, 01, 10, and 11. In some embodiments, 00 may correspond to a predetermined threshold current value that is used in the automatic drive operation of the toggle module. . 520. In this way, the absence of a signal during a starting period can correspond to the binary value 00. As an example, the current threshold values corresponding to the different binary signals can include 6.3kA, 500A, 8kA and 10kA.

The arc flash drive circuit 506 can provide a reliable voltage (V ^cc ) to the three toggle modules 520 after the first 2 seconds from the start and can transfer the alarm signal of the arc flash detection system 64 to the three lever modules 520 without introducing any delay after the first 2 seconds from power up.

In some example embodiments, toggle module 520 may be actuated when the current through the power line is above I ^th peak for a period of more than 2 ms. In that case, only the toggle module 520 that is connected to the corresponding power line is automatically actuated whenever the current rises above I ^th . In some embodiments, the response time of lever module 520 once actuated is around 300 ps.

Some embodiments envision that toggle module 520 can also be actuated when there is an alarm signal from arc flash detection system 64. In that case, all three toggle modules 520 are actuated until main circuit breaker 68 is activated. Some embodiments envision that the response time of the toggle module 520 once actuated is less than 2 ms and can typically be around 300 ps. Thereafter, toggle module 520 will be in continuous drive for a period of 100 ms.

Some embodiments envision that an arc flash and overload protection system may include a toggle module such as an electronic switch that is connected in series with an energy absorber. In such applications, there are TOVs (surges) in the system that could damage the equipment. In this sense, a solution to direct part of the energy to a device that absorbs it can be advantageous. Some embodiments include an energy absorber that may be based on multiple metal oxide varistors (MOVs) that are connected in parallel to absorb the TOV event. For example, the voltage can be fixed during such an event by turning on the MOVs to conduct some current when the voltage increases.

For example, for a 240 V system, the maximum voltage is 336 V. Using a MOV with a maximum continuous operating voltage (MCOV) of 250 VAC as close to the rated voltage as possible can be used such that during normal conditions the MOV does not conduct any current. The MOV can conduct a very small leakage current (~1mA) at 336V. However, as the voltage increases, the MOV can start to conduct a lot in an effort to limit the voltage. In this case, the voltage cannot exceed the value of 1000V maximum.

However, there are power systems that may need protection at much lower voltage levels, for example 700 V instead of 1000 V. In such cases, to reduce the level of protection, MOVs with a lower MCOV can be used. ie thinner MOV discs. For example, the mOv may have an MCOV of 150 VAC instead of 250 VAC. In such cases, in normal operation, the MOV can carry a significant current (above a few amps) that will force it to fail within a limited period of time (depending on the exact level of current carried). In this regard, an energy absorber can be used with a MOV having an MCOV of 150 VAC in series with each other.

For example, reference is now made to Figure 29, which is a schematic block diagram illustrating an overload protection system used in equipment protection in accordance with some embodiments of the present invention. As illustrated, the arc flash, overvoltage, overcurrent, and overload protection system 600 may include a toggle device 602 that is connected between the different phase lines L1, L2, L3. Lever device 602 can be connected in series with several MOVs 605 that are connected to respective ones of the plurality of phase lines L1, L2, L3.

The toggle device 602 can function as a switch that will connect the MOVs 605 which function as energy absorbers for the phase lines only when the voltage exceeds a given threshold. In some embodiments, the given threshold is approximately 600 V, however this is simply a non-limiting example. 605 MOVs can drive as much current as is needed to keep the voltage below 700V. As an example, based on the voltage-current curve of a 150VAC MOV, at 700V the 605m Ov can drive 10KA of current, which exceeds the current that the TOV can produce. As such, the phase lines L1, L2, L3 cannot reach the 700V level.

Also, when the sinusoidal system voltage decreases to cross the zero level, the impedance of the MOV will increase and limit the current through the thyristor in the crowbar module 602. Next, when the current through the thyristor in the crowbar 602 drops below 200 mA, the thyristor will disconnect the energy absorber from the system. This can occur as soon as the system voltage drops below the maximum of approximately 280V.

Brief reference is now made to Figure 30, which is a schematic block diagram illustrating a lever device as briefly described above with respect to Figure 29, according to some embodiments of the present invention. Lever device 602 may include a plurality of thyristors TH1, TH2, TH3 that are connected between different pairs of the plurality of phase lines L1, L2, L3. A toggle drive circuit 630 may include a rectifying circuit 632 that receives three-phase alternating current from the plurality of phase lines L1, L2, L3 and generates a corresponding DC signal. Lever drive circuit 630 may include a comparator 634 which receives the DC signal and a reference voltage Vr and compares the two signals. If the DC signal exceeds the reference voltage Vr, then the comparator 634 generates an output to a plurality of drive controllers 636 that are configured to fire the thyristors into a conducting mode in response thereto. Once the DC signal drops below the reference voltage Vr, then the comparator 634 output changes state and the 636 drive controllers turn off the thyristors.

Reference is now made to Figure 31, which is a schematic block diagram illustrating a surge protection system 60 used in protective equipment according to some embodiments of the present invention. Instead of the line-to-line connection described above with respect to Figures 29 and 30, the arc flash, overvoltage, overcurrent, and overload protection system may include a toggle device 700 that includes MOVs 705 that are connected in series with modules. each phase line L1, L2, L3 to neutral N. Since each phase line includes a separate MOV 705/toggle 720 module combination, then a fault on an individual phase line can be addressed without actuating the combination of the MOV 705/lever module 720 of the other phase lines. Brief reference is now made to Figure 32, which is a schematic block diagram illustrating a lever module as briefly described above with respect to Figure 31, in accordance with some embodiments of the present invention. A lever device actuation circuit 730 may include a rectification circuit 732 which receives an AC phase current from a phase line and generates a corresponding DC signal. Lever drive circuit 730 may include a comparator 734 which receives the DC signal and a reference voltage signal Vr and compares the two received signals. If the DC signal exceeds the reference voltage Vr, then comparator 734 generates an output to a drive controller 736 which then drives an opto-isolator 738. The output of opto-isolator 738 is configured to drive thyristors TH1, TH2 in a driving mode in response to it. Once the DC signal drops below the reference voltage Vr, then the output of comparator 734 changes state and drive controller 736 turns off thyristors TH1, TH2.

Referring to Figures 33-35, a lever system 800 according to other embodiments of the invention is shown therein. Lever system 800 includes lever device 802 (corresponding to lever device 502 in Figure 24), drive and alarm interface circuit unit 806 (corresponding to drive circuit 506 in Figure 24), and selector. remote threshold selector 807 (corresponding to threshold selector 510 of FIG. 24).

Referring to Figure 33, toggle device 800 includes three toggle modules 810, three SPDs 804, a neutral conductor NB, line conductors L1B, L2B, L3B, and three current sensors 805. Toggle device 800 includes furthermore a lever device housing 860 (shown in broken lines) within which the lever modules 810, SPD 804, conductors NB, L1B, L2B, L3B, and current sensors 805 are mounted, arranged and encased.

In some embodiments, the drive and alarm interface circuit unit 806 and remote selector switch 807 are located outside the toggle housing 860. For example, the drive and alarm interface circuit unit 806 may be located elsewhere in an electrical service cabinet containing toggle device 802 and lines L1, L2, L3 so that actuation and alarm interface circuit unit 806 is better positioned for operator access or to detect activity in the cabinet. Remote selector switch 807 may be located a substantial distance (eg, at least 20 feet) from toggle device 802. For example, toggle device 802 may be located high above the ground on a tower while the switch 807 remote selector is mounted near ground level to allow convenient access by an operator.

Lever modules 810 correspond to lever modules 520 in Figure 24. Each of the lever modules 810 is electrically and mechanically coupled to the neutral conductor NB (corresponding to the neutral line N) and one of the respective line conductors L1B, L2B, L3B (corresponding to lines L1, L2, L3).

A respective SPD 804 (corresponding to SPDs 104 in Figure 24; for example, a MOV-based SPD) is mounted between the associated line conductor and electrically connects it L1B, l2b, L3B and the neutral conductor NB in parallel to the associated lever module 810.

Current sensors 805 correspond to current sensors 505. Each of the current sensors 805 is operatively mounted on one of the respective line conductors L1B, L2B, L3B and has an output signal cable 805A connected to the output module. associated lever 810.

Each toggle module 810 is also electrically connected via an electrical cable 806A to the drive and alarm interface circuit unit 806. The remote selector switch 807 is in turn electrically connected to the interface circuit unit 806 by an electrical cable. 807A.

Lever modules 810 may be constructed and operated generally as described herein with respect to lever module 210, except as described below. Each module 810 may include a fill material corresponding to fill material 218; however, this fill material is not shown in Figure 35.

Referring to Figures 34 and 35, the lever module 810 includes a module housing 811 that defines a closed chamber 811A. The module housing 811 includes an outer cover 812, a removable cover or back plate 813, and a base plate 815. The outer cover 812 is provided with a rear side opening 812A. The opening 812A is closed and environmentally sealed by a removable cover or back plate 813. The interface between the back plate 813 and the cover 812 around the opening may be hermetically sealed by a rubber seal 813A. In some embodiments, chamber 811A is hermetically sealed or moisture sealed.

Referring to Figure 35, lever units 801, 803 corresponding to lever units 201, 202 and a circuit board assembly 830 corresponding to circuit board assembly 230 are arranged in chamber 811A between a set of coil 820 (corresponding to coil assembly 220) and a base bus 814.

Circuit board assembly 830 may include a snubber circuit corresponding to the snubber circuit of circuit board assembly 230.

An internal circuit board assembly 833 is secured to back plate 813 in chamber 811A. The internal circuit board assembly 833 may include the automatic lever actuation circuit 530 of the control module. Lever 520 of Figures 25 and 26. Advantageously, placing drive circuit 530 in lever module housing 811 in close proximity to thyristors TH1, TH2 can reduce or prevent noise induced in the leads that might otherwise drive the thyristors. thyristors TH1, TH2 accidentally.

An electrical connector 813B is mounted on back plate 813 to electrically connect leads 805A, 806A to circuit board assembly 830, circuit board assembly 833, and lever unit thyristors 801,803. The 813B electrical connector may be environmentally sealed.

Various inventive aspects as described herein may be used independently of one another. For example, a lever unit 201 including a grommet 280 as described can be used without unitarily mounting the lever unit 201 with a coil, busbars, a damper circuit, or another lever unit.

Claims (18)

1. A circuit protection device comprising: an electric arc, overvoltage, overcurrent and overload protection system (100) that is connected between a plurality of phase lines (L1, L2, L3) and a neutral line (N) that are located between a power supply line input and an electrical load panel (62) in an electrical equipment, or that is connected between the plurality of phase lines (L1, L2, L3); where: a) the protection system against electric arc, overvoltage, overcurrent and overload includes: a lever device (102) that is coupled to the plurality of phase lines (L1, L2, L3) and to the neutral line (N) and is configured to avoid an overvoltage condition by generating through at least one thyristor a path low resistance current from the plurality of phase lines to the neutral line; a plurality of surge protection devices (104) that are connected to the plurality of phase lines and to the neutral line and that are configured to protect the equipment during an overvoltage condition by conducting a limited amount of current corresponding to the overvoltage condition overvoltage; Y a toggle drive circuit (106) that is configured to cause the toggle device to turn on and provide the low resistance current path from one of the plurality of phase lines to the neutral line; or b) the protection system against electric arc, overvoltage, overcurrent and overload includes: a toggle device that is coupled to and between the plurality of phase lines (L1, L2, L3) and is configured to prevent an overvoltage condition by selectively generating through at least one thyristor a low-resistance current path between the plurality of phase lines; a plurality of surge protection devices that are connected to and between the plurality of phase lines and that are configured to protect the equipment during an overvoltage condition by conducting a limited amount of current corresponding to the overvoltage condition; Y a toggle drive circuit that is configured to cause the toggle device to turn on and provide the low resistance current path between the plurality of phase lines; Y characterized in that the lever actuation circuit comprises: a plurality of thyristor drive circuits (168) that are configured to generate thyristor drive signals that are received by the lever device; a power source and a voltage hold circuit (166) that is configured to receive electrical power for the lever actuation circuit and to provide power to the lever actuation circuit for a period of time after power is lost electrical for lever actuation circuit; Y an interface circuit (164) that is configured to receive inputs corresponding to voltages from the plurality of phase lines, current flow through the plurality of phase lines, an arc signal, and/or temperatures from respective devices overload protection. The device according to claim 1, wherein the lever actuation circuit further comprises a microcontroller (162) that is configured to receive data from the interface circuit, process the received data, and generate and send actuation signals to one or more than the plurality of thyristor drive circuits, an alarm signal to a remote warning device and/or a drive signal to a main circuit breaker (68). 3. The device according to claim 1, wherein the protection system against electric arc, overvoltage, overcurrent and overload comprises: a toggle device (102) that is coupled to the plurality of phase lines and the neutral line and is configured to prevent an overvoltage condition by generating a low resistance current path from the plurality of phase lines to the neutral line; a plurality of surge protection devices (104) that are connected to the plurality of phase lines and to the neutral line and that are configured to protect the equipment during an overvoltage condition by conducting a limited amount of current corresponding to the overvoltage condition overvoltage; Y a toggle drive circuit (106) that is configured to cause the toggle device to turn on and provide the low resistance current path from one of the plurality of phase lines to the neutral line. The device according to claim 3, wherein the toggle device comprises a plurality of surge protection modules (120) that are coupled between respective lines of the plurality of phase lines and the neutral line. The device according to claim 4, wherein one of the plurality of surge protection modules (120) each comprises: a bidirectional thyristor (TH1, TH3, TH5; Figure 10); Y an inductor (L) that is connected in series with the bidirectional thyristor. The device according to claim 4, wherein one of the plurality of surge protection modules (120) each comprises: two thyristors (TH1, TH2, TH3, TH4, TH5, TH6; Figure 5) that are connected antiparallel to each other; and an inductor (L) that is connected in series with the two thyristors. The device according to claim 6, wherein the ones of the plurality of surge modules further comprise a snubber circuit that is connected in parallel with the two thyristors, wherein the snubber circuit comprises a resistor (R) and a capacitor (C) They are connected in series with each other. The device according to claim 3, wherein the arc flash, overvoltage, overcurrent, and overload protection system further comprises an arc flash detection system (64) that is configured to detect an arc flash within the equipment and to generate and send an electrical arc signal to the lever actuation circuit. The device according to claim 3, wherein the power source and voltage hold circuit (166) comprises: a plurality of DC-DC converters (186) each operable to provide voltages to one of the plurality of thyristor drive circuits; Y a hold circuit (184) that is configured to hold a voltage that is provided to the plurality of DC-DC converters. 10. The device according to claim 3, wherein the lever device comprises: a plurality of pairs of antiparallel connected thyristors that are coupled between respective ones of the plurality of phase lines and the neutral line; a plurality of inductors that are connected in series with respective ones of the plurality of pairs of antiparallel thyristors; Y a plurality of surge protection devices that are connected between the respective ones of the plurality of phase lines and the neutral line. 11. The device according to claim 1, wherein the protection system against electric arc, overvoltage, overcurrent and overload comprises: a toggle device that is coupled to and between the plurality of phase lines and is configured to prevent an overvoltage condition by selectively generating a low resistance current path between the plurality of phase lines; a plurality of surge protection devices that are connected to and between the plurality of phase lines and that are configured to protect the equipment during an overvoltage condition by conducting a limited amount of current corresponding to the overvoltage condition; Y a toggle drive circuit that is configured to cause the toggle device to turn on and provide the low resistance current path between the plurality of phase lines. 12. The device according to claim 3, wherein the protection system against electric arc, overvoltage, overcurrent and overload comprises: an arc drive circuit (506) that is configured to cause the toggle device to turn on and provide the low resistance current path from one of the plurality of phase lines to the neutral line, wherein the toggle device comprises a plurality of self-actuating toggle modules (520) that are connected to the neutral line and respective ones of the plurality of phase lines. The device according to claim 12, wherein the plurality of self-actuating lever modules (520) each comprise: two thyristors (TH1, TH2) that are connected antiparallel to each other; an inductor (L) that is connected in series with the two thyristors; a lever actuation circuit (530) that is configured to receive a current signal from a current sensor on the corresponding one of the plurality of phase lines and to cause at least one of the two thyristors to provide a current path of low resistance between the corresponding one of the plurality of phase lines and the neutral line in response to the current signal exceeding a current threshold. The device according to claim 13, wherein the lever drive circuit is configured to generate a drive signal in the absence of any signal from the arc drive circuit (506). 15. The device according to claim 13, wherein the lever drive circuit is configured to provide automatic actuation of the corresponding one of the plurality of lever modules during an equipment start-up period, and wherein the arc flash drive circuit (506) is configured to drive the plurality of toggle modules in response to detection of an arc flash after the equipment start-up period. 16. The device according to claim 13, wherein the plurality of lever modules further comprise a damper circuit that is connected in parallel with the two thyristors, and wherein the damper circuit comprises a resistor (R) and a capacitor (C) that are connected in series with each other. The device according to claim 12, wherein the arc flash, overvoltage, overcurrent, and overload protection system further comprises an arc flash detection system (64) that is configured to detect an arc flash within the equipment and to generating and sending an arc flash signal to the arc flash drive circuit (506). 18. The device according to claim 12, wherein the arc flash, overvoltage, overcurrent, and overload protection system further comprises a threshold selector (510) that is connected to the arc flash drive circuit (506) and is configured to provide a threshold current selection signal corresponding to a current threshold value.